2007 Dynasty No START - Voltage to Big Boy zero - UPDATE - Issue was AIR IN FUEL FILTERS.

[John C]

Just noticed my chassis batteries where not charged. checked the Big Boy, the input voltage to Big Boy is zero, the chassis battery is 12.64V, After I shutdown the chassis battery switch, the battery went up to 12.79V after 1 hr
Could anyone please tell me what (fuse?) control the input voltage to the Big Boy? I noticed there are two wires connected to the Big Boy , but can't figure out anything from there.

Is it possible that the relay from the house battery shut the voltage to zero because 12.6v or 12.79v is high enough so it won't need to charge it?

Right now I can't start the coach (I assume it is not enough juice on chassis batter) so I don't know if the alternator will charge the chassis battery or not.

Actually I did started the engine this afternoon once after many tries, it only last less than one minute and then the engine stopped, hopefully it is related to the chassis battery and not somewhere else.

I am also having problem starting the generator.

I just Google and found out that 12.6V is a normal chassis battery range and that should be able to start the engine.

Maybe this is something else???

Please help.

 

Thank you.
2007 Dynasty.

[TomV48]

Not sure I fully unde5stand your problem.  My "not brand name" BIG BOY, is activated by ird IRD, to allow the chassis/alternator to cross charge the house batteries.  It has a power lead from the IRD which only becomes hot,  after the alternator replenishes the chassis batteries comes up a bit from starting the engine.   

If there is no  power to the relay windings from the IRD board,  there should still be house voltage on one side of the relay and chassis voltage on the other side.

If there is no power on the chassis side I guess you back track from there.  All the way back to the alternator if need be.  Is the alternator charging the chassis battery ?

[John C]

13 hours ago, TomV48 said:

Not sure I fully unde5stand your problem.  My "not brand name" BIG BOY, is activated by ird IRD, to allow the chassis/alternator to cross charge the house batteries.  It has a power lead from the IRD which only becomes hot,  after the alternator replenishes the chassis batteries comes up a bit from starting the engine.   

If there is no  power to the relay windings from the IRD board,  there should still be house voltage on one side of the relay and chassis voltage on the other side.

If there is no power on the chassis side I guess you back track from there.  All the way back to the alternator if need be.  Is the alternator charging the chassis battery ?

PER PHONE CONVERSATION WITH JOHN…

There are some errors and misunderstanding as he had a poor or perhaps intermittent ground.

Just posted an update….therefore, working off this may be futile.

He asked for it to be edited..

END OF EDIT

If I understand it correctly, there is no power on the relay from the house, there are two studs on the Big Boy, one stud test Zero Voltage(I assume it is from the house to the relay) another stud is 12.63V which is the exactly the same voltage as I directly tested the chassis battery, so I assume this stud is connected to the chassis battery.

Because the stud from the house relay is zero, it is not charging my chassis battery.

Right now I can't start the coach (I assume it is not enough juice on chassis batter) so I don't know if the alternator will charge the chassis battery or not.

Actually I did started the engine this afternoon once after many tries, it only last less than one minute and then the engine stopped, hopefully it is related to the chassis battery and not somewhere else.

I am also having problem starting the generator because of the low chassis battery.

 

[MyronTruex]

Just noticed my chassis batteries were not charged. checked the Big Boy, the input voltage to Big Boy is zero, the chassis battery is 12.64V, After I shutdown the chassis battery switch, the battery went up to 12.79V after 1 hr This is just a normal surface charge rising with no load.
Could anyone please tell me what (fuse?) control the input voltage to the Big Boy? I noticed there are two wires connected to the Big Boy , but can't figure out anything from there.

Sorry, I can’t help with what fuse or what system exactly you have such as an IRD or a BIRD. You may have the system that pulses the control power to the Big Boy. In any case, disconnect the control wire and use a small jumper to take power from the large terminal post to the small post you just disconnected. The BB should go clunk and combine the battery banks to get you charging while you diagnose the issue.

Is it possible that the relay from the house battery shut the voltage to zero because 12.6v or 12.79v is high enough so it won't need to charge it? No, the charging voltage can go close to 14 volts at times and I don’t think your charging/combining system is smart enough to quit charging a bank when it is fully charged. It looks at the batteries as one combined back.

Right now I can't start the coach (I assume it is not enough juice on chassis batter) so I don't know if the alternator will charge the chassis battery or not. Once you get enough charge on the engine batteries to start it you can remove the small jumper and measure the voltage to see if it is charging the batteries. Once your coach batteries are charged more your generator should start better. You should be able to get the generator running after a few minutes of the alternator running. Keep the big engine running while you start the generator. Once you have things charged up a bit you can start chasing the control line issue down. Someone here much more familiar with your setup will be along shortly as the sun comes up.

Actually I did started the engine this afternoon once after many tries, it only last less than one minute and then the engine stopped, hopefully it is related to the chassis battery and not somewhere else.

I am also having problem starting the generator.

 

[Dr4Film]

Lots of searchable information on those Big Boys here that has been posted over the years including one really good one by our forum owner, David Pratt.

I have chosen not to use the Big Boy but rather the Blues Seas ML-ACR which comes with its own control "brain".

[Tom Cherry]

11 hours ago, John C said:

Just noticed my chassis batteries where not charged. checked the Big Boy, the input voltage to Big Boy is zero, the chassis battery is 12.64V, After I shutdown the chassis battery switch, the battery went up to 12.79V after 1 hr
Could anyone please tell me what (fuse?) control the input voltage to the Big Boy? I noticed there are two wires connected to the Big Boy , but can't figure out anything from there.

Is it possible that the relay from the house battery shut the voltage to zero because 12.6v or 12.79v is high enough so it won't need to charge it?

Right now I can't start the coach (I assume it is not enough juice on chassis batter) so I don't know if the alternator will charge the chassis battery or not.

Actually I did started the engine this afternoon once after many tries, it only last less than one minute and then the engine stopped, hopefully it is related to the chassis battery and not somewhere else.

I am also having problem starting the generator.

I just Google and found out that 12.6V is a normal chassis battery range and that should be able to start the engine.

Maybe this is something else???

Please help.

 

Thank you.
2007 Dynasty.

OK…gonna be long…..

MANY THINGS GOING ON…. 

I’d do this…..and read carefully….

TURN OFF BOTH DISCONNECT SWITCHES.  Take JUMPER cables from a vehicle and hook UP to the Chassis bank.  Start the vehicle….let it RUN for a few minutes.  NOW turn back on the two battery switches….  Let the vehicle run.  Use your VOM.  The Chassis SHOULD be around 14.0 or so….that will vary with the vehicle….let it run for a few more minutes.  That is putting a Surface Charge on the chassis…. NOW FIRE UP THE ENGINE…..let it run….should be OK…..

You are NOW charging the Chassis bank.  OK…I WROTE THE FOLLOWING…as I skimmed your post….

NOW you can address and test the BIG BOY…

First….you should downoad and look at the prints….I’ll send you a PM with the link and the MAIN High Current/Low Voltage later today….but start reading….let both engines run while you do….

HERE’s the PRIMER on the BIG BOY and how it works..

The Big Boy is controlled by a Pulsed Voltage signal from board #6 in the Rear Run Bay.  That board is powered, directly from your House snd Chassis Disconnect switches.  There are 4 terminals on each switch.  Obviously the two large studs are HIGH CURRENT. BUT, the two small terminals are just a “second set of contacts” to send “operating voltage” to board #6. That board also controls the “BOOST” function as well….and also (memory) the TOWED vehicle (Ignition switch ON) charging current.  Make SURE that you have voltage to GROUND on each of the small terminals on EACH disconnect switch….

When the Big Boy is working properly on a Dynasty, there is a “13.1 or Float VDC” signal sent to the terminals of the Big Boy. So, that VOLTAGE is pulsed.  Two of our members, @Frank McElroy and @pwhittle.  These guys can repair, replace the chip, reprogram and FIX the board…probably between them, they have done 50 or more.

OK….what is the VOLTAGE and how or what does PULSED mean. The full 13.1 signal is actually being turned on and off…maybe 20 times per second….divide 1,000 (milliseconds) by 20….the length of the pulse could be 50 milliseconds….so, the pulse actually stays ON for about 35 milliseconds….then shuts off for 15 milliseconds…..SIMPLE EXPLANATION….if you put a VOM on the terminals, you will read about 8 VDC.  The VOM just “averages” the pulsed ON voltage.  WHY…

PURE & SIMPLE.  The coil in the Big Boy is NOT RATED for a FULL 12-13 VDC.  It will BURN UP…but feed it a lower voltage (average) and it will HUM and be happy.  It will ALSO be so hot to the touch, you can’t close and keep your hand around it,  PERFECTLY NORMAL and designed that way.  If, when the engine is running and/or plugged into 50A (or Genny is on)….YOU HEAR NO HUM/BUZZ and the can is cool….IT AIN’T Working……as in the coil is bad or…LIKE YOURS…. the #6 board ain’t working 

NOTE to other owners….Camelot  and on down.  They don’t have a BOARD 6…just an Intellitec BIRD module.  The hum is FAINT…it is WARM…but not burn you HOT.  Intellitec regulates the voltage to about half that of the #6 board….if you read anything above 3-3.2 VDC…..ITS OK and WORKING.

OK….now you know….NO 8 or so VDC on the terminals….PROBLEM with board #6….or your batteries are perfectly charged.  SO…odds are…bad #6 board.

PM Frank or Paul….and they can fix the board….

BUT….you ALSO need to see the condition of the Big Boy…because this puppy is ON almost 100% when you have the Engine running, the contacts get arced and pitted.  Start the engine.  Have someone up front push, when you signal over cellphones, the BOOST button.  The BOOST will, sometimes,  WORK.  If it goes CLUNK…it has engaged.  Have your VOM ready.  Measure the Voltage on each large stud to GROUND.  Should be the same….but….if there is more than a TENTH (0.1 or maybe 0.2) DIFFERENCE….the contacts need maintenance.  NOW put your VOM across the two large studs…should be 0.00 VDC…if above 0.2 VDC….time to clean it.  BUT…DON’T have your helper hold for more than 30 second….if you can’t get all 3 readings….let if sit for a few minutes and get the final one.

The FACT that it went CLUNK….that means the COIL works…there is a simple cleaning procedure in the files.  Folks with very little “MH Savvy” have cleaned them in less than 30 minutes.

THATS IT….

[Paul J A]

2 hours ago, Dr4Film said:

Lots of searchable information on those Big Boys here that has been posted over the years including one really good one by our forum owner, David Pratt.

I have chosen not to use the Big Boy but rather the Blues Seas ML-ACR which comes with its own control "brain".

THAT is the solution once and for all.  Great devise.

[John C]

19 minutes ago, Tom Cherry said:

First….go to the wiring diagrams….

The Big Boy is controlled by a Pulsed Voltage signal from board #6 in the Rear Run Bay.  That board is powered, directly from your House snd Chassis Disconnect switches.  There are 4 terminals on each switch.  Obviously the two large studs are HIGH CURRENT. BUT, the two small terminals are just a “second set of contacts” to send “operating voltage” to board #6. That board also controls the “BOOST” function as well….and also (memory) the TOWED vehicle (Ignition switch ON) charging current.  Make SURE that you have voltage to GROUND on each of the small terminals on EACH disconnect switch….

When the Big Boy is working properly on a Dynasty, there is a “13.1 or Float VDC” signal sent to the terminals of the Big Boy. So, that VOLTAGE is pulsed.  One of our members, @Frank McElroy is the expert….as well as @pwhittle.  These guys can repair, replace the chip, reprogram and FIX the board…probably between them, they have done 50 or more.

OK….what is the VOLTAGE and how or what does PULSED mean. The full 13.1 signal is actually being turned on and off…maybe 20 times per second….divide 1,000 (milliseconds) by 20….the length of the pulse could be 50 milliseconds….so, the pulse actually stays ON for about 35 milliseconds….then shuts off for 15 milliseconds…..SIMPLE EXPLANATION….if you out a VOM on the terminals, you will read about 8 VDC.  The VOM just “averages” the pulsed ON voltage.  WHY…

PURE & SIMPLE.  The coil in the Big Boy is NOT RATED for a FULL 12-13 VDC.  It will BURN UP…but feed it a lower voltage (average) and it will HUM and be happy.  It will ALSO be so hot to the touch, you can’t close and keep your hand around it,  PERFECTLY NORMAL and designed that way.  If, when the engine is running and/or plugged into 50A (or Genny is on)….YOU HEAR NO HUM/BUZZ and the can is cool….IT AIN’T Working…

NOTE to other owners….Dynasty and down.  They don’t have a BOARD 6…just an Intellitec BIRD module.  The hum is FAINT…it is WARM…but not burn you HOT.  Intellitec regulates the voltage to about half that of the #6 board….if you read anything above 3-3.2 VDC…..ITS OK and WORKING.

OK….now you know….NO 8 or so VDC on the terminals….PROBLEM with board #6….or your batteries are perfectly charged.  SO…odds are…bad #6 board.

PM Frank or Paul….and they can fix the board….

BUT….you ALSO need to see the condition of the Big Boy…because this puppy is ON almost 100% when you have AC power or Engine running, the contacts get arced and pitted.  Start the engine.  Have someone up front push, when you signal over cellphones, the BOOST button.  The BOOST will, sometimes,  WORK.  If it goes CLUNK…it has engaged.  Have your VOM ready.  Measure the Voltage on each large stud to GROUND.  Should be the same….but….if there is more than a TENTH (0.1 or maybe 0.2) DIFFERENCE….the contacts need maintenance.  NOW put your VOM across the two large studs…should be 0.00 VDC…if above 0.2 VDC….time to clean it.  The FACT that it went CLUNK….that means the COIL works…there is a simple cleaning procedure in the files.  Folks with very little “MH Savvy” have cleaned them in less than 30 minutes.

THATS IT….

Just tried the boost function, the battery voltage went up from 11.8 to 12.2v on the dashboard, but when I tried to started the engine, it drop like a rock all the way to the bottom, after a few tries, still can't start the e ngine.

5 hours ago, MyronTruex said:

Just noticed my chassis batteries were not charged. checked the Big Boy, the input voltage to Big Boy is zero, the chassis battery is 12.64V, After I shutdown the chassis battery switch, the battery went up to 12.79V after 1 hr This is just a normal surface charge rising with no load.
Could anyone please tell me what (fuse?) control the input voltage to the Big Boy? I noticed there are two wires connected to the Big Boy , but can't figure out anything from there.

Sorry, I can’t help with what fuse or what system exactly you have such as an IRD or a BIRD. You may have the system that pulses the control power to the Big Boy. In any case, disconnect the control wire and use a small jumper to take power from the large terminal post to the small post you just disconnected. The BB should go clunk and combine the battery banks to get you charging while you diagnose the issue.

Is it possible that the relay from the house battery shut the voltage to zero because 12.6v or 12.79v is high enough so it won't need to charge it? No, the charging voltage can go close to 14 volts at times and I don’t think your charging/combining system is smart enough to quit charging a bank when it is fully charged. It looks at the batteries as one combined back.

Right now I can't start the coach (I assume it is not enough juice on chassis batter) so I don't know if the alternator will charge the chassis battery or not. Once you get enough charge on the engine batteries to start it you can remove the small jumper and measure the voltage to see if it is charging the batteries. Once your coach batteries are charged more your generator should start better. You should be able to get the generator running after a few minutes of the alternator running. Keep the big engine running while you start the generator. Once you have things charged up a bit you can start chasing the control line issue down. Someone here much more familiar with your setup will be along shortly as the sun comes up.

Actually I did started the engine this afternoon once after many tries, it only last less than one minute and then the engine stopped, hopefully it is related to the chassis battery and not somewhere else.

I am also having problem starting the generator.

 

could you please elaborate on "disconnect the control wire and use a small jumper to take power from the large terminal post to the small post you just disconnected."

Thank you.

2 hours ago, Dr4Film said:

Lots of searchable information on those Big Boys here that has been posted over the years including one really good one by our forum owner, David Pratt.

I have chosen not to use the Big Boy but rather the Blues Seas ML-ACR which comes with its own control "brain".

That is my future plan but need to start the engine right now...

[Tom Cherry]

5 minutes ago, Paul J A said:

THAT is the solution once and for all.  Great devise.

YES….and it costs less…but, one has to run a separate wire bundle from the back to the front.  Then pull and discard the OEM boost switch and then wire the Blue Seas switch in, properly.  Not everyone’s idea of fun.  If the Big Boy is working, 30 minutes will be all that is needed to clean the contacts.  Frank McElroy and Paul Whittle can repair the #6 board to OEM quality for a nominal sum….maybe 20% of what the other “shop” gets…

 

IF you take power, as in 12 VDC, as suggested….hooking up a FULL 12 VDC will burn up the coil.  Your manual and the PDF for the BIG BOY warn against that…

I just UPDATED my post…read it.

[Paul J A]

1 minute ago, Tom Cherry said:

YES….and it costs less…but, one has to run a separate wire bundle from the back to the front.  Then pull and discard the OEM boost switch and then wire the Blue Seas switch in, properly.  Not everyone’s idea of fun.  If the Big Boy is working, 30 minutes will be all that is needed to clean the contacts.  Frank McElroy and Paul Whittle can repair the #6 board to OEM quality for a nominal sum….maybe 20% of what the other “shop” gets…

 

THE results are well worth the effort . NO more Big Boy maintenance.  

Here is the link Frank McElroy posted on the installation of the ML-ACR.  Sounds like it's a 2 or 3 wire "bundle".

 

[Tom Cherry]

12 hours ago, John C said:

If I understand it correctly, there is no power on the relay from the house, there are two studs on the Big Boy, one stud test Zero Voltage(I assume it is from the house to the relay) another stud is 12.63V which is the exactly the same voltage as I directly tested the chassis battery, so I assume this stud is connected to the chassis battery.

Because the stud from the house relay is zero, it is not charging my chassis battery.

Right now I can't start the coach (I assume it is not enough juice on chassis batter) so I don't know if the alternator will charge the chassis battery or not.

Actually I did started the engine this afternoon once after many tries, it only last less than one minute and then the engine stopped, hopefully it is related to the chassis battery and not somewhere else.

I am also having problem starting the generator because of the low chassis battery.

 

The above post, per conversation with John, is in error.  He has NOT had a good ground.  That is why he is confused even more,

We talked.

He HAS cleaned, thanks to a conversation with Frank several months ago, the Big Boy and things appeared to work.

He ALSO has the MH on a 20 A circuit…but probably did not understand that he needed to change the Magnum setup.  

He used a small battery charger and tried to charge the Chassis.  Obviously they are depleted.  Do NOT know, but GUESSING, that the Chassis did not have enough current or reserve to get past the preheated element (air intake heaters) cycle 

The Chassis was so depleted that they would not even supply the needed 200 or so amps…for the Generator.  NOTE…he has the undersized Generator cables….so it usually DOES take a fully charged chassis battery to start the Generator.

He NOW understands how the system works or it is starting to sink in.  He has a clear path, as suggested, to surface charge, after PROPERLY hooking up a Vehicle battery…and then charging…for 5-10 minutes….turning back on both banks….then another 5 - 10 minutes of surface charging…. THEN….try the engine.

IF it starts or doesn’t, he will then be able to start the generator….then let both the vehicle run and also the generator.

At some point, he now understands how to properly TEST the control voltage (pulsed) signal that should be coming from Board #6.

He measured that voltage, he thinks, with nothing on except the 20A adapter and there would NOT have been enough current for the #6 board to function.

He has appointments…so he will be doing all this later today or maybe tomorrow….

So, lets let him start the proper troubleshooting for this system…..and see what happens and what he reports….

He has also not been maintaining the electrolyte level in the house…so…their condition???  Who knows.

Thats the GIST…..

[John C]

9 hours ago, Tom Cherry said:

The above post, per conversation with John, is in error.  He has NOT had a good ground.  That is why he is confused even more,

We talked.

He HAS cleaned, thanks to a conversation with Frank several months ago, the Big Boy and things appeared to work.

He ALSO has the MH on a 20 A circuit…but probably did not understand that he needed to change the Magnum setup.  

He used a small battery charger and tried to charge the Chassis.  Obviously they are depleted.  Do NOT know, but GUESSING, that the Chassis did not have enough current or reserve to get past the preheated element (air intake heaters) cycle 

The Chassis was so depleted that they would not even supply the needed 200 or so amps…for the Generator.  NOTE…he has the undersized Generator cables….so it usually DOES take a fully charged chassis battery to start the Generator.

He NOW understands how the system works or it is starting to sink in.  He has a clear path, as suggested, to surface charge, after PROPERLY hooking up a Vehicle battery…and then charging…for 5-10 minutes….turning back on both banks….then another 5 - 10 minutes of surface charging…. THEN….try the engine.

IF it starts or doesn’t, he will then be able to start the generator….then let both the vehicle run and also the generator.

At some point, he now understands how to properly TEST the control voltage (pulsed) signal that should be coming from Board #6.

He measured that voltage, he thinks, with nothing on except the 20A adapter and there would NOT have been enough current for the #6 board to function.

He has appointments…so he will be doing all this later today or maybe tomorrow….

So, lets let him start the proper troubleshooting for this system…..and see what happens and what he reports….

He has also not been maintaining the electrolyte level in the house…so…their condition???  Who knows.

Thats the GIST…..

@Tom CherryThank you SO MUCH for your help this morning, I learned a lot today.

I was busy the whole day and didn't get a chance to work on it until now.

I followed your advice as following:

1) shutdown both chassis disconnect switch and house battery switch

2) Connect my car battery with coach chassis battery with jumper

3) Start my car

4) let it sit for 10 minutes

5) turn on chassis battery disconnect switch and house disconnect swtich

6) wait for 5 minutes

7) Start the coach

Unfortunately, it won't start, even the battery on the dashboard is more than 13v. Please see video & photo below

https://photos.app.goo.gl/WyGFbsgrZGky2qydA

So I guess I have two problems

1) The big boy is not charging my chassis's battery

2) The Starter or somewhere in the Engine has a problem

When I turn on the key without trying to start the coach, the "Check Engine" light is on. But After I tried to start the coach a few times, the light went away.

Looks like I got more serious problem in addition to the Big Boy problem(BB is minor because I am going to install lithium and solar this week and will get rid of it anyway

Does any one know how to retrieve the error code?

What kind of the starter do I need?

Maybe there is for another thread.

Thanks again.

[Tom Cherry]

Try to start the Generator without using your car as a Jumper.  If the Generator will not start, then, most likely, the Chassis Bank is “dead”…as in needs replacing. Even though you can read good voltage on the bank, they have no cranking power.

If that doesn’t work….  Disconnect both battery banks.  Put a Jumper cable across the positive terminals.  Reconnect or turn on the battery switches. Start the generator.  Let it run for 3 hours or so.  The Magnum is charging BOTH BANKS…..that eliminates the Big Boy.

With the generator still running, try to start the Engine.  This totally eliminates the chassis batteries.  If the engine doesn’t turn over, then there is a problem.

Could be something simple in the starting system…failed relay or loose connection.  Could be worse.

Just randomly saying “bad starter” and putting one in without trouble shooting the chassis starting system may be a waste of time snd money.

You have to identify the problem….then replace….not just guess and start throwing parts at it.

 

 

[cbr046]

9 hours ago, John C said:

Does any one know how to retrieve the error code?

 

On my 03 ISC Endeavor / Diplomat there's an "ENG/DIAG" switch.  With ignition 'on' and engine not running press & hold either the top or bottom part of the switch.  While holding it down the warning and stop engine lights will light, go out and the warning light will flash a 3 digit code.  It will repeat the code for as long as you hold the switch.   There's a list of fault codes at https://thecampingadvisor.com/spn-cummins-fault-codes-list/  (scroll down to Tier4) but you'll really want to log into your Cummins quickserve account for a more detailed explanation of the codes and how to repair.  In QuickServe click on tabs Service then . . . . I forget, but it's one of the tabs in the middle of the page.

Good luck.

- bob

[Tom Cherry]

57 minutes ago, cbr046 said:

On my 03 ISC Endeavor / Diplomat there's an "ENG/DIAG" switch.  With ignition 'on' and engine not running press & hold either the top or bottom part of the switch.  While holding it down the warning and stop engine lights will light, go out and the warning light will flash a 3 digit code.  It will repeat the code for as long as you hold the switch.   There's a list of fault codes at https://thecampingadvisor.com/spn-cummins-fault-codes-list/  (scroll down to Tier4) but you'll really want to log into your Cummins quickserve account for a more detailed explanation of the codes and how to repair.  In QuickServe click on tabs Service then . . . . I forget, but it's one of the tabs in the middle of the page.

Good luck.

- bob

GOOD INFORMATION.  Monaco swapped dash and gauge clusters like a rock star does costume changes during s show.  These switches were part of the “gauge package”.  

The only way to find out is to read the Chassis (section 9) snd Chassis Electrical (sectioN 8 ) of John’s owher’s manual. My guess is he has the ACTI brand or vendor…..memory.  He can research….

Thanks

[MyronTruex]

Since you asked this question. 

"could you please elaborate on "disconnect the control wire and use a small jumper to take power from the large terminal post to the small post you just disconnected."

This is my response:

The two small terminals control an electromagnet. A simple magnet that pulls in a heavy set of contacts inside the solenoid. You can remove the wires that are connected and supply your own 12 volts on one and a ground on the other. This should engage the solenoid to allow you to then check the voltages on each large terminal which should then be the same.

You may get a small spark when using your own light weigh jumper wires but don't panic. The clunk of the solenoid should be a surprise as well.

You have lots of great advice beyond this but you may still be curious. 

[Bob Blackmon]

23 hours ago, Tom Cherry said:

YES….and it costs less…but, one has to run a separate wire bundle from the back to the front.  Then pull and discard the OEM boost switch and then wire the Blue Seas switch in, properly.  Not everyone’s idea of fun.  If the Big Boy is working, 30 minutes will be all that is needed to clean the contacts.  Frank McElroy and Paul Whittle can repair the #6 board to OEM quality for a nominal sum….maybe 20% of what the other “shop” gets…

 

IF you take power, as in 12 VDC, as suggested….hooking up a FULL 12 VDC will burn up the coil.  Your manual and the PDF for the BIG BOY warn against that…

I just UPDATED my post…read it.

You do not have to run any additional wires. There is already a wire going from the boost switch to J1 pin 2 of board 6. Cut it and attach to the red wire on the ACR. Wire ground and power to the switch as outlined in the schematic. This will give you auto, boost and off to the ACR. There is nothing on these coaches that require any more of the features of the ML ACR.

[John C]

3 hours ago, Tom Cherry said:

Try to start the Generator without using your car as a Jumper.  If the Generator will not start, then, most likely, the Chassis Bank is “dead”…as in needs replacing. Even though you can read good voltage on the bank, they have no cranking power.

If that doesn’t work….  Disconnect both battery banks.  Put a Jumper cable across the positive terminals.  Reconnect or turn on the battery switches. Start the generator.  Let it run for 3 hours or so.  The Magnum is charging BOTH BANKS…..that eliminates the Big Boy.

With the generator still running, try to start the Engine.  This totally eliminates the chassis batteries.  If the engine doesn’t turn over, then there is a problem.

Could be something simple in the starting system…failed relay or loose connection.  Could be worse.

Just randomly saying “bad starter” and putting one in without trouble shooting the chassis starting system may be a waste of time snd money.

You have to identify the problem….then replace….not just guess and start throwing parts at it.

 

 

Just tried the same step, I was able to start the generator but still couldn't start the engine.

When I tried to start the engine while the generator was on, it shut downed the generator. I have something fishy going on on the generator, that will be for another post.

The "check engine" light showed up when I just turn on the key without start the engine. no sure if it is a because the "check engine" light error that prevented me from start the engine.

I just ordered a tester to check the capacity of battery and will use it to test the chassis battery, if it is no good, them I will replace the chassis battery (need to do that anyway regardless the engine condition).

I will order a code reader on the Cummins engine, hopefully it is something small, otherwise I will probably call a mobile semi-truck repair - definitely don't want the coach be towed unless I have no choice.

I will post another thread on the generator.

Thank you.

 

[John C]

3 hours ago, cbr046 said:

On my 03 ISC Endeavor / Diplomat there's an "ENG/DIAG" switch.  With ignition 'on' and engine not running press & hold either the top or bottom part of the switch.  While holding it down the warning and stop engine lights will light, go out and the warning light will flash a 3 digit code.  It will repeat the code for as long as you hold the switch.   There's a list of fault codes at https://thecampingadvisor.com/spn-cummins-fault-codes-list/  (scroll down to Tier4) but you'll really want to log into your Cummins quickserve account for a more detailed explanation of the codes and how to repair.  In QuickServe click on tabs Service then . . . . I forget, but it's one of the tabs in the middle of the page.

Good luck.

- bob

Unfortunately I did not see that switch on my Dynasty.

That switch would be very nice and handy for me now.

[Tom Cherry]

21 minutes ago, John C said:

Just tried the same step, I was able to start the generator but still couldn't start the engine.

When I tried to start the engine while the generator was on, it shut downed the generator. I have something fishy going on on the generator, that will be for another post.

The "check engine" light showed up when I just turn on the key without start the engine. no sure if it is a because the "check engine" light error that prevented me from start the engine.

I just ordered a tester to check the capacity of battery and will use it to test the chassis battery, if it is no good, them I will replace the chassis battery (need to do that anyway regardless the engine condition).

I will order a code reader on the Cummins engine, hopefully it is something small, otherwise I will probably call a mobile semi-truck repair - definitely don't want the coach be towed unless I have no choice.

I will post another thread on the generator.

Thank you.

 

WHOA...  We don't need multiple threads. SO HOLD OFF on the Generator.

Let's REVIEW

This is what we just discussed.  PERSONALLY, your 2 year old chassis batteries may be totally dead as in NOT taking a charge.  

BUT....you just told me that the Generator will NOT run for more than 10 Minutes....so using the Jumper Cable between the Two Banks and letting the Genny run for several hours is OUT.

You are going to locate a 50 Amp Extension cable and provide 50 Amps to the Magnum.  You will have the BANKS jumpered together and then let that "cook" for 24 hours or so.  You will also monitor, say every 4 hours or so, the remote charging current on the Magnum.  It will be a max and BULK.  If it does NOT start to drop and then go to absorb and finally FLOAT, then ODDS ARE...the Chassis will NOT take a charge. BUT, you WILL try to start the Engine.  What happened, and did NOT connect the House to the Chassis,, but used the Jumper Cables....when you jumped off the Generator....and then tried to start the Engine...the current draw was great enough to totally wipe or or cause a major voltage drop and then the AUTO SHUT DOWN DUE TO LOW VOLTAGE of the Generator kicked in.

Let us know in a day or so what is going on...  BUT, bottom line....if all this fails...you will then take the Chassis batteries to a battery shop (Interstate...and should be one around the LA area) and have them tested...if they are totally DEAD...then purchase TWO new Chassis.

BUT, if they say they are GOOD or OK...then time for a Mobile Mechanic....and you have the Prints to help him.

GOOD LUCK...

THAT HAPPENS.  Then, you will 

 

 

[John C]

15 minutes ago, Tom Cherry said:

WHOA...  We don't need multiple threads. SO HOLD OFF on the Generator.

Let's REVIEW

This is what we just discussed.  PERSONALLY, your 2 year old chassis batteries may be totally dead as in NOT taking a charge.  

BUT....you just told me that the Generator will NOT run for more than 10 Minutes....so using the Jumper Cable between the Two Banks and letting the Genny run for several hours is OUT.

You are going to locate a 50 Amp Extension cable and provide 50 Amps to the Magnum.  You will have the BANKS jumpered together and then let that "cook" for 24 hours or so.  You will also monitor, say every 4 hours or so, the remote charging current on the Magnum.  It will be a max and BULK.  If it does NOT start to drop and then go to absorb and finally FLOAT, then ODDS ARE...the Chassis will NOT take a charge. BUT, you WILL try to start the Engine.  What happened, and did NOT connect the House to the Chassis,, but used the Jumper Cables....when you jumped off the Generator....and then tried to start the Engine...the current draw was great enough to totally wipe or or cause a major voltage drop and then the AUTO SHUT DOWN DUE TO LOW VOLTAGE of the Generator kicked in.

Let us know in a day or so what is going on...  BUT, bottom line....if all this fails...you will then take the Chassis batteries to a battery shop (Interstate...and should be one around the LA area) and have them tested...if they are totally DEAD...then purchase TWO new Chassis.

BUT, if they say they are GOOD or OK...then time for a Mobile Mechanic....and you have the Prints to help him.

GOOD LUCK...

THAT HAPPENS.  Then, you will 

 

 

Tom,

Thanks again for your help.

Just ordered an extension, it will arrive tomorrow and I will try those thing you talked about.

Will definitely report on the progress once I get the extension.

[John C]

On 6/4/2024 at 10:04 AM, Tom Cherry said:

WHOA...  We don't need multiple threads. SO HOLD OFF on the Generator.

Let's REVIEW

This is what we just discussed.  PERSONALLY, your 2 year old chassis batteries may be totally dead as in NOT taking a charge.  

BUT....you just told me that the Generator will NOT run for more than 10 Minutes....so using the Jumper Cable between the Two Banks and letting the Genny run for several hours is OUT.

You are going to locate a 50 Amp Extension cable and provide 50 Amps to the Magnum.  You will have the BANKS jumpered together and then let that "cook" for 24 hours or so.  You will also monitor, say every 4 hours or so, the remote charging current on the Magnum.  It will be a max and BULK.  If it does NOT start to drop and then go to absorb and finally FLOAT, then ODDS ARE...the Chassis will NOT take a charge. BUT, you WILL try to start the Engine.  What happened, and did NOT connect the House to the Chassis,, but used the Jumper Cables....when you jumped off the Generator....and then tried to start the Engine...the current draw was great enough to totally wipe or or cause a major voltage drop and then the AUTO SHUT DOWN DUE TO LOW VOLTAGE of the Generator kicked in.

Let us know in a day or so what is going on...  BUT, bottom line....if all this fails...you will then take the Chassis batteries to a battery shop (Interstate...and should be one around the LA area) and have them tested...if they are totally DEAD...then purchase TWO new Chassis.

BUT, if they say they are GOOD or OK...then time for a Mobile Mechanic....and you have the Prints to help him.

GOOD LUCK...

THAT HAPPENS.  Then, you will 

 

,

@Tom Cherry, Here is updates.

1) shutdown both chassis disconnect switch and house battery switch

2) Connect my house battery with coach chassis battery with jumper

3) connected to shore power

4) turn on chassis battery disconnect switch and house disconnect switches

5) wait overnight

6) Start the coach

 

I tried those step on 20 amps shore power (before I received the 50 amps power cord extension) and 50 amps shore power., it made no difference, still can not start the engine. now the "check engine" light is always one. I will receive the code reader today, will see what the error code is.

I then connected the battery tester to the chassis battery with and without the chassis batteries connected to the house batteries.

When the chassis batteries was connected to the house batteries and tried to start the engine, the tested showed OK. (Maybe OK for normal car but 10 v may not good enough for my coach)

When the chassis batteries was NOT connected to the house batteries , the tested showed NOT OK.  the lowest battery voltage is 8.8V

So the chassis Batteries are definitely no good (enough). I will replace the chassis battery and see what happens.

Will keep you updated.

When the chassis batteries is connected to the house batteries, the test is No OK

 

Unfortunately, it won't start, even the battery on the dashboard is more than 13v. Please see video & photo below

 

[Dr4Film]

Your batteries are toast!

[Tom Cherry]

6 minutes ago, John C said:

@Tom Cherry, Here is updates.

1) shutdown both chassis disconnect switch and house battery switch

2) Connect my house battery with coach chassis battery with jumper

3) connected to shore power

4) turn on chassis battery disconnect switch and house disconnect switches

5) wait overnight

6) Start the coach

 

I tried those step on 20 amps shore power (before I received the 50 amps power cord extension) and 50 amps shore power., it made no difference, still can not start the engine. now the "check engine" light is always one. I will receive the code reader today, will see what the error code is.

I then connected the battery tester to the chassis battery with and without the chassis batteries connected to the house batteries.

When the chassis batteries was connected to the house batteries and tried to start the engine, the tested showed OK. (Maybe OK for normal car but 10 v may not good enough for my coach)

When the chassis batteries was NOT connected to the house batteries , the tested showed NOT OK.  the lowest battery voltage is 8.8V

So the chassis Batteries are definitely no good (enough). I will replace the chassis battery and see what happens.

Will keep you updated.

When the chassis batteries is connected to the house batteries, the test is No OK

 

Unfortunately, it won't start, even the battery on the dashboard is more than 13v. Please see video & photo below

 

Well, it is NOW clear.   For whatever reason, the Chassis batteries FAILED. Get s new set.  Many of us, some with way more experience than me, opt for the top end Interstate MHD-950…. That code may be off a little.  Group 31 with studs and CCA of 950 CCA. Each.  

Even though you were reading above 12.5 or so OPEN CIRCUIT (No Load) voltage, there are internal issues and the batteries will not take a charge.  Nothing can be done to salvage.  It happens.  It COULD have been one shorted out…when that happens the imbalance of the charging takes it’s toll.

OK…get it running.   THEN repeat your tests of the Big Boy.  The board #6 is designed to keep from destroying the OTHER bank when there is a bad (as in yours) bank.  With the engine running, you should see (after 5 minutes to run and stabilze, the Big Boy start to BUZZ and eventually heat up.  The voltage on each stud….with a GOOD GROUND should be equal…and reading very low or no more than 0.1-0.2 VDC across the Studs.

IF NOT.. Then try the boost….if it click or slams in….and the volatges are equal, obviously a defective board #6. Paul or Frank can repair.

Good Luck…

 

 

[John C]

59 minutes ago, Tom Cherry said:

Well, it is NOW clear.   For whatever reason, the Chassis batteries FAILED. Get s new set.  Many of us, some with way more experience than me, opt for the top end Interstate MHD-950…. That code may be off a little.  Group 31 with studs and CCA of 950 CCA. Each.  

Even though you were reading above 12.5 or so OPEN CIRCUIT (No Load) voltage, there are internal issues and the batteries will not take a charge.  Nothing can be done to salvage.  It happens.  It COULD have been one shorted out…when that happens the imbalance of the charging takes it’s toll.

OK…get it running.   THEN repeat your tests of the Big Boy.  The board #6 is designed to keep from destroying the OTHER bank when there is a bad (as in yours) bank.  With the engine running, you should see (after 5 minutes to run and stabilze, the Big Boy start to BUZZ and eventually heat up.  The voltage on each stud….with a GOOD GROUND should be equal…and reading very low or no more than 0.1-0.2 VDC across the Studs.

IF NOT.. Then try the boost….if it click or slams in….and the volatges are equal, obviously a defective board #6. Paul or Frank can repair.

Good Luck…

 

 

Well, the reason is clear, Big Boy failed me even I rebuild it one month ago and I didn't noticed that, that caused irreversible damage to the chassis battery.

For new chassis battery, are you talking about this one?
https://www.interstatebatteries.com/products/31-mhd

I will buy two of those today tomorrow.

I am done with Big Boy and will change it with DC-DC charge with Lithium  battery. On my lithium & solar project I will definitely need your guys guidance on that.

Thank you!