No 12 volt power in the coach

[bmulvenna@hotmail.com]

2004 Dynasty

Sorry posted in the wrong category.

1. No 12 volt in the coach.

2. BigBoy and both house and engine solenoids have been eleminared for well over a year. No sales switch.

3. House batteries meter at 13. 2 volts indicating they are charging

4. Xantrex rv2012 inverter shows float Charging.

5. 13.2 volts output from house battery disconnect switch.

6. Should show 13.2 volts input to all house terminals in the rear run box.

7. Testing each RRB house positive terminal using a chassis ground only show 1.4 volts. This is true even if the house batteries are disconnected with the main disconnect switch. 

8. Testing those same RRB house positive terminals using the house battery negative post shows 13.2

9. Input and output to and from the inverter shows 13.2 volts.

Appears to be a chassis ground issue.

Any thoughts on a solution greatly appreciated.

Edited August 31, 2023 by bmulvenna@hotmail.com

[vito.a]

I would start by checking the battery ground cable in the basement next to the inverter.  While in there, also check the main positive battery cables. 

Next check the ground cable from the house batteries to the frame back by the battery compartment.   Also check the battery disconnect switch cables on the backside of the battery compartment.  

Hope you find it!

[bmulvenna@hotmail.com]

After disconnecting the batteries from the RRB there is still 1.3 volts at the RRB. Tomorriw will Disconnect EACH RRB cable to see which one is feeding the 1.3 voltage 

13 minutes ago, vito.a said:

I would start by checking the battery ground cable in the basement next to the inverter.  While in there, also check the main positive battery cables. 

Next check the ground cable from the house batteries to the frame back by the battery compartment.   Also check the battery disconnect switch cables on the backside of the battery compartment.  

Hope you find it!

Thanks, already done all of that.

[Tom Cherry]

7 hours ago, bmulvenna@hotmail.com said:

2004 Dynasty

Sorry posted in the wrong category.

1. No 12 volt in the coach.

2. BigBoy and both house and engine solenoids have been eleminared for well over a year. No sales switch.

3. House batteries meter at 13. 2 volts indicating they are charging

4. Xantrex rv2012 inverter shows float Charging.

5. 13.2 volts output from house battery disconnect switch.

6. Should show 13.2 volts input to all house terminals in the rear run box.

7. Testing each RRB house positive terminal using a chassis ground only show 1.4 volts. This is true even if the house batteries are disconnected with the main disconnect switch. 

8. Testing those same RRB house positive terminals using the house battery negative post shows 13.2

9. Input and output to and from the inverter shows 13.2 volts.

Appears to be a chassis ground issue.

Any thoughts on a solution greatly appreciated.

Maybe….and i had a different issue as in Genny (House starts it) would not turn over….

Try this.  Use Jumper Cables…turn off both disconnects.  Jumper the positives and the negatives of the House and Chassis.  Turn on both disconnects.  See if that fixes.  
My issue was a bad ground.  Behind the battery area, should be the Negative cables.  Both chassis and house go to separate studs.  Pull cables.  Clean and retighten.  Then test.

OK…. You can “hunt & peck” or do it the old fashioned logical way.  Get a length of #16 or so hookup wire.  You will also need two double ended test leads with alligator clips on each end.

Here’s the drill.  Assume nothing.  Put an alligator clip lead on the battery positive bolt/post.  Attach to your hookup wire.  Put the other alligator lead on the other end of the wire.  Then hook that up to the common on your VOM.  Use the 12 VDC scale.  Now, physically trace the positive cable to the first point or lug where it is attached.  Use the meter probe and measure the voltage.  It should be zero or maybe a few hundredths….it depends on the length.  

You have a bad or high resistance connection or you have a cable with corrosion inside the terminal.  You can’t see it.  The only way is to measure…under load.  Then, move the alligator clip from the positive terminal to where you just measured.  Then go to the next point where a cable is connected.  If the cable goes through the disconnect, then measure the other contact.  Eventually, you will find a bad connection.  This is more foolproof than measuring to ground…as the cable or switch or connection terminal is under load.  We have had folks swear the cables were GREAT….but they had several volts potential over the cable.  They cut off the cable end.  OPPS…totally corroded.

Don’t know if you have the “through the box” connections.  Measure every point, starting at the battery post using this method.  It tells you the continuity of the cable…or whatever .

You’ll spend less time than checking points to ground.  Unless you had a bad ground (see first paragraph), then this is the correct way to isolate.

Let us know…

 

 

 

[bmulvenna@hotmail.com]

Thanks Tom. Will try what you suggested, but don't forget there is 1.4 volts at the house battery connections on the RRB even though the battery is not connected to it as indicated in my post number 7

13 hours ago, Tom Cherry said:

Maybe….and i had a different issue as in Genny (House starts it) would not turn over….

Try this.  Use Jumper Cables…turn off both disconnects.  Jumper the positives and the negatives of the House and Chassis.  Turn on both disconnects.  See if that fixes.  
My issue was a bad ground.  Behind the battery area, should be the Negative cables.  Both chassis and house go to separate studs.  Pull cables.  Clean and retighten.  Then test.

OK…. You can “hunt & peck” or do it the old fashioned logical way.  Get a length of #16 or so hookup wire.  You will also need two double ended test leads with alligator clips on each end.

Here’s the drill.  Assume nothing.  Put an alligator clip lead on the battery positive bolt/post.  Attach to your hookup wire.  Put the other alligator lead on the other end of the wire.  Then hook that up to the common on your VOM.  Use the 12 VDC scale.  Now, physically trace the positive cable to the first point or lug where it is attached.  Use the meter probe and measure the voltage.  It should be zero or maybe a few hundredths….it depends on the length.  

You have a bad or high resistance connection or you have a cable with corrosion inside the terminal.  You can’t see it.  The only way is to measure…under load.  Then, move the alligator clip from the positive terminal to where you just measured.  Then go to the next point where a cable is connected.  If the cable goes through the disconnect, then measure the other contact.  Eventually, you will find a bad connection.  This is more foolproof than measuring to ground…as the cable or switch or connection terminal is under load.  We have had folks swear the cables were GREAT….but they had several volts potential over the cable.  They cut off the cable end.  OPPS…totally corroded.

Don’t know if you have the “through the box” connections.  Measure every point, starting at the battery post using this method.  It tells you the continuity of the cable…or whatever .

You’ll spend less time than checking points to ground.  Unless you had a bad ground (see first paragraph), then this is the correct way to isolate.

Let us know…

 

 

 

 

[bmulvenna@hotmail.com]

FOUND THE ISSUE.

Negative cable from the inverter is connected to a stud that is welded to the frame. It was not making a connection thru the stud to the frame. Disconnected cable and jump it to the frame and issue is temporarily resolved. Now need to make a permanent connection to the frame.

[Tom Cherry]

39 minutes ago, bmulvenna@hotmail.com said:

FOUND THE ISSUE.

Negative cable from the inverter is connected to a stud that is welded to the frame. It was not making a connection thru the stud to the frame. Disconnected cable and jump it to the frame and issue is temporarily resolved. Now need to make a permanent connection to the frame.

Well good.  GROUNDS, as I said, are elusive But…. The welded stud is not, statistically, the problem.  I got a text  saying ….well, if it rusted off, then It IS the problem….  LOL and the expert says the same as me.  A welded stud that has a clean area under where a vable end goes is not thr problem….either there is hidden corrosion snd disassembly and cleaning will fix…or BAD end terminal.

If there was no corrosion visible on the cable end, then try this. Clean the area around the stud.  Bare metal.  Now clean the negative end of the House cable.  Hook back up.  No joy….there is an issues in the cable.  Probably internal corrosion inside the crimped on end.  Looks fine outside…but a mess on the inside.  

But, if you want 100% proof.  There is probably a CHASSIS STUD nearby.  Swap the cables.  Odds are the issue will follow the cable.  Mine was corrosion hidden under the nut on the stud.  All I had to do was loosen and then rotate the cable 120 degrees a few time to burnish or clean the surfaces.  Ground studs are usually fool proof…that’s why they are welded.  Swapping the chassis and house will either show a “bad stud” or a bad cable.

If you had used a jumper cable between the negatives….house and chassis, that would have isolated it.  Adding a “drilled & tapped” ground is way inferior to the traditional welded stud…

Good luck.  Keep us posted

[bmulvenna@hotmail.com]

Thanks. The cable is good. No corrosion on cable or stud. Wire brushed stud and cable anyway. No joy. Attach cable to frame and all works.

[Tom Cherry]

4 minutes ago, bmulvenna@hotmail.com said:

Thanks. The cable is good. No corrosion on cable or stud. Wire brushed stud and cable anyway. No joy. Attach cable to frame and all works.

So, a welded stud, with no visible rust, after cleaning and a clean cable end, reattached and properly tightened did not fix it.  But using the same cable end and drilling a hole and putting in a bolt to the frame fixed it?  Wow…weird.  Personally, I would disconnect the Chassis cable and put it on the same stud.  If it fails…then we have a new way of frustrating an owner.  BUT, if it works and no issues, then my guess is that the cable end has internal issues and moving it around and manipulating it reconnected the crimp, temporarily, inside it.  If that is the case, it will fail again.  Not based on suppositions but past events with a few members.  

I would NOT leave home without Jumper cables as eventually, the internal arcing will  come back and you have the same high resistance connection…and the simple fix is to connect the house and chassis grounds.  One of late (rip) electrical experts chased exactly what you are experiencing…finally just cut off the end.  Totally corroded on the inside, but no exterior as he had kept it sprayed.  If you had measured the voltage, when the condition occurred from one cable end to the other…with everything hooked up, I suspect you would have seen the “voltage” across the cable was high and not Zero…that is the only way to test the ends…

Could be wrong…have been before…but moving a defective (internal crimp) cable may temporarily fixed things…but will give you the opportunity to chase again.  A welding shop can fix with a new end quickly.  Many of us carry the terminals and a hydraulic crimper…especially when we get intermittent failures or voltage drops

Thats my thinking…but your MH…keep us posted…

[bmulvenna@hotmail.com]

Tom,

Thanks.  I did not drill a hole

 I attached a jumper to the inverter ground cable and the other end of the jumper to the frame. Need to deside on permanent solution.

Edited September 3, 2023 by bmulvenna@hotmail.com

[bmulvenna@hotmail.com]

On 8/31/2023 at 6:43 PM, vito.a said:

I would start by checking the battery ground cable in the basement next to the inverter.  While in there, also check the main positive battery cables. 

Next check the ground cable from the house batteries to the frame back by the battery compartment.   Also check the battery disconnect switch cables on the backside of the battery compartment.  

Hope you find it!

Vito.a

after I found my issue I was re-reading the posts in this thread. As it turns out you hit the nail on the head. It was the battery ground from the inverter not making a good connection thru the welded stud. Thanks for your input. 

Edited September 3, 2023 by bmulvenna@hotmail.com
Spelling

[Tom Cherry]

Talked to another expert.  Welded studs do not go bad.  Take that to the bank.  Cables and terminals do.  Adding a non welded stud will not be as good as a welded one.  The only way to properly troubleshoot a “connection” problem is to put everything back to normal. Clean all connections and check the tightness.  Put a load on the system like having lights turned on or a motor (slide) running.  Then use a VOM and do a voltage test on each cable (terminal to terminal) or across a connection, circuit breaker, or switch.  If you don’t have a load, the voltage will look great.  But when you have a high resistance connection, the amps go up (ain’t good for the motor…I know for a fact) and that drives down the voltage.  

Your original issue was very high.  Adding a ground, a good one, regardless of where, indicates a real problem.  On most MH, there is one “main” chassis ground.  See the pictures below.  Note the size of the cables.  The 4/0 is on a common ground in the House.  Note the same concept for the Chassis.  That is by design so the that a good ground goes to the frame and to the most critical point….inverter for house and starter for chassis….in effect, they are bonded. There are many other welded studs then “downstream” for the dash, generator (starting/charging), peripherals like key engine grounds.

It the bonded connection to ground for either bank is bad due to corrosion or “road grime” or “cable issue”, then the results will vary.  If you clean both the chassis and house studs, reconnect the cables, after cleaning, and still have a problem….it is NOT in the welded stud.  There is a problem with the ground cable from the battery.  The simple way…jumper cable the banks.  Then that fixes it……..whichever system, house or chassis was the issue….assuming the cables on each bank are clean and tight….bad ground cable.  Measuring, with a load on that system will show a voltage potential across the cable terminal ends.  Should be ZERO… but a few hundreds might be there.

Thats just the way you isolate and test.  I spent years chasing a one volt drop.  It burned up my hydraulic slide motor.  Fortunately, i had. 200 Amp CHASSIS connection in the FRB.  I put in a selector switch and then ran my slides off the chassis.  Just last fall, I was doing some PM.  Bingo.  Found the issue.  My house disconnect was showing, no load, a half volt drop on the terminals.  The switch was the issue.  You could drive and it vibrates and is fine…other times not.

So, now, i will put in a new one.  I went through the drill and had my wife cycling the slides….from every cable and terminal.  If it ain’t broke when you test or do the voltage test…it ain’t gonna show…. Never found it as driving home, the switch would be OK and the slide moved normally.

That’s the drill and the logic….hope you find itmis just a matter or cleaning…but from what you said….if you grounded the inverter cable…then that fixed it…then there is a high resistance connection at the common stud…and you have “jumpered” that.  So, clean and put back together.  If no joy, then use the hookup wire and alligator clips and check each cable…has to be in a cable….nowhere else…

[bmulvenna@hotmail.com]

Thanks Tom. Appreceiate your help.

There is nothing else connected to that stud.

I have it working connected to a different frame ground.

Edited September 3, 2023 by bmulvenna@hotmail.com
Correction

[vito.a]

Good job tracking it down.  I'm glad you found it. 

[Tom Cherry]

1 hour ago, bmulvenna@hotmail.com said:

Thanks Tom. Appreceiate your help.

There is nothing else connected to that stud.

I have it working connected to a different frame ground.

That may or may NOT be the issue.  You need to go to the prints.  Probably towards the end in your manual.  The Print is 38010014. Called Low Volt High Current Diagram.  This explains WHY you have an issue and where it potentially can be.

I have attached the print as well as a screen shot from my monitor.

You are going to have to look at you inverter.  All I can do is go by the prints.  There is an INCOMING Ground from the Battery (Negative to the main Inverter Ground cable.  Then, IT LOOKS....so you have to verify  like there is a separate GROUND from the Inverter to the chassis.  SO, I don't know what the Trace cabinet looks like.  A picture SURE would help.  The issue is that from the "schematic", it looks that there are TWO Grounds from the Trace.  They are INTERNALLY CONNECTED and BONDED.  That is the ONLY WAY to get the House Battery GROUND to the Chassis Stud.  NOW, Monaco always does thing crazy...so Prints aren't always correct.  But you can bet on ONE THING.  If there is only ONE 4/0 Negative from the Battery box....it has to go to a GROUND....and later on, it was like the print I posted....or it has to have a pathway.  SO, trace the negative from the Battery to wherever it is terminated.  If there is only ONE Cable, as the print shows, then it should be on the Back side of the Inverter or next to wherever the positive is.  THEN, the Inverter has to have a BONDED, INTERNAL High Current Connection to the GROUND STUD.  That, per the print, is the only way.  

OK....taking this one step further, assuming you found only ONE Negative from the House Battery bank....if the internal Bond (inside the Trace is bad....then NO GROUND.  BUT, if the internal Bond is good, then the ONLY pathway to Ground is the external ground.  Bear in mind...I'm doing this from prints without the benefit of pictures.

Therefore, it is a SAFE bet that the stud is OK....welded studs may rust....but if the stud is attached....that is NOT the issue.  SO....there are some points of connection that have to be looked at or verified.  First....the cable between the GROUND stud going to the Inverter.  If I understood you, you hooked up a Jumper Cable.  It was on the EXTERNAL Ground....where the Inverter to Ground runs.  Then you put it to Ground.  BINGO....all works.  Therefore the cable from the external Ground to the Chassis Stud is defective. 

BUT, if you hooked up the Jumper Cable from the INCOMING Battery (Negative terminal...beside the Positive....then you should move that cable to the EXTERNAL GROUND and see if that fixes it.  If that does NOT, then the internal bond between the Incoming Negative and the External Ground is BAD...as in INSIDE the inverter.

So, run the tests.  Isolate where the high resistance connection is.  You ae going to have to go back with a reliable cable from the original ground stud...to the external ground stud.  UNLESS you decide to JUMPER from the Battery (incoming) to the External.  And THAT will work...but the isues in the inverter may, if that is the cause, have to be addressed.  

Pictures and comments...so we can isolate.

 

High Current Battery 2004 Dynasty - Signature 38010014.pdf

[bmulvenna@hotmail.com]

1 hour ago, Tom Cherry said:

That may or may NOT be the issue.  You need to go to the prints.  Probably towards the end in your manual.  The Print is 38010014. Called Low Volt High Current Diagram.  This explains WHY you have an issue and where it potentially can be.

I have attached the print as well as a screen shot from my monitor.

You are going to have to look at you inverter.  All I can do is go by the prints.  There is an INCOMING Ground from the Battery (Negative to the main Inverter Ground cable.  Then, IT LOOKS....so you have to verify  like there is a separate GROUND from the Inverter to the chassis.  SO, I don't know what the Trace cabinet looks like.  A picture SURE would help.  The issue is that from the "schematic", it looks that there are TWO Grounds from the Trace.  They are INTERNALLY CONNECTED and BONDED.  That is the ONLY WAY to get the House Battery GROUND to the Chassis Stud.  NOW, Monaco always does thing crazy...so Prints aren't always correct.  But you can bet on ONE THING.  If there is only ONE 4/0 Negative from the Battery box....it has to go to a GROUND....and later on, it was like the print I posted....or it has to have a pathway.  SO, trace the negative from the Battery to wherever it is terminated.  If there is only ONE Cable, as the print shows, then it should be on the Back side of the Inverter or next to wherever the positive is.  THEN, the Inverter has to have a BONDED, INTERNAL High Current Connection to the GROUND STUD.  That, per the print, is the only way.  

OK....taking this one step further, assuming you found only ONE Negative from the House Battery bank....if the internal Bond (inside the Trace is bad....then NO GROUND.  BUT, if the internal Bond is good, then the ONLY pathway to Ground is the external ground.  Bear in mind...I'm doing this from prints without the benefit of pictures.

Therefore, it is a SAFE bet that the stud is OK....welded studs may rust....but if the stud is attached....that is NOT the issue.  SO....there are some points of connection that have to be looked at or verified.  First....the cable between the GROUND stud going to the Inverter.  If I understood you, you hooked up a Jumper Cable.  It was on the EXTERNAL Ground....where the Inverter to Ground runs.  Then you put it to Ground.  BINGO....all works.  Therefore the cable from the external Ground to the Chassis Stud is defective. 

BUT, if you hooked up the Jumper Cable from the INCOMING Battery (Negative terminal...beside the Positive....then you should move that cable to the EXTERNAL GROUND and see if that fixes it.  If that does NOT, then the internal bond between the Incoming Negative and the External Ground is BAD...as in INSIDE the inverter.

So, run the tests.  Isolate where the high resistance connection is.  You ae going to have to go back with a reliable cable from the original ground stud...to the external ground stud.  UNLESS you decide to JUMPER from the Battery (incoming) to the External.  And THAT will work...but the isues in the inverter may, if that is the cause, have to be addressed.  

Pictures and comments...so we can isolate.

 

High Current Battery 2004 Dynasty - Signature 38010014.pdf 528.75 kB · 0 downloads

Tom. I have said that I already have this schematic and I have looked at it a number of times over the past few days.

The inverter does have its own ground. That is the one that I moved to a new frame ground and now all is well.

Everything is running  the way it is supposed to and I am leaving it at that, as the way I see it, the issue is resolved.

Thanks for your input. We are away from the coach for a number of days so I can't get any pictures.

Thanks again. 

Edited September 3, 2023 by bmulvenna@hotmail.com
Spelling

[Tom Cherry]

11 minutes ago, bmulvenna@hotmail.com said:

Tom. I have said that I already have this schematic and I have looked at it a number of times over the past few days.

The inverter does have its own ground. That is the one that I moved to a new frame ground and now all is well.

Everything is running  the way it is supposed to and I am leaving it at that, as the way I see it, the issue is resolved.

Thanks for your input. We are away from the coach for a number of days so I can't get any pictures.

Thanks again. 

Good luck.  You posted.
 

Negative cable from the inverter is connected to a stud that is welded to the frame. It was not making a connection thru the stud to the frame. Disconnected cable and jump it to the frame and issue is temporarily resolved. Now need to make a permanent connection to the frame.

The stud is NOT carrying the current or the load.  Carry a jumper cable.  Moving a bad cable will often break loose the internal corrosion inside a cable.  The purpose of welded stud is to allow the terminal to be clamped directly to a bare spot on the frame.  The surface contact from the frame to the battery terminal flat surface is what carries the current or the load….not the stud.  As long as you can tighten down the flat terminal and the frame contact area and terminal contact area makes good mechanical joint, that that is all that is needed.  The stud just supplies a method of clamping two metal surfaces.

I certainly hope this continues to work….but this has been done before…and many times, it fails as the arcing or corrosion inside the cable end returns. So, if moving or wiggling the cable caused a better connection on the Inverter terminal or moved the cables inside the ground terminal end….fixed it…. Great.  Based on the prints, I am a bit suspicious of the area under inverter ground stud being clean and having the proper mechanical joint….and that could have been the bad connection….as in the surfaces of the stud’s contact area and the cable end were corroded….  Many times we see this.  They look OK…but don’t work.  The fix is to barely loosen, rotate terminal from side to side under tension…bingo, the contact area get abraded or burnished or polished… That might have been it all along…

The point is that many of these fixes just reoccur and then plague folks.  If it flares up again, please use this original topic to respond and not start a new one. We, the staff and members, try to use our best knowledge and experience…but sometimes just “messin” with it corrects a problem.  So…leave it at that, but understand the root cause was a high resistance connection and that usually cleaning and retightening will be sufficient….but there is no cause…such as a bad stud…as it is only the clamp…and not designed to carry the high current.

Lets let it run its course….glad it is working….  You may never have an issue…but if you do….I believe the inverter ground stud is near the chassis bank.  Jumper from the chassis negative to the inverter ground cable end…on the inverter.  That will provide a ground….as long as the bonded ground inside the inverter is OK.

Thanks….

 

 

[bmulvenna@hotmail.com]

The inverter ground stud is in the front  storage bay (clean area) next to the inverter and that  is the one that had the issue. I guess we are just not understanding each other.  Guess we agree to disagree , the issue is resolved.

Edited September 3, 2023 by bmulvenna@hotmail.com

[Tom Cherry]

2 hours ago, bmulvenna@hotmail.com said:

The inverter ground stud is in the front  storage bay (clean area) next to the inverter and that  is the one that had the issue. I guess we are just not understanding each other.  Guess we agree to disagree , the issue is resolved.

As I said, pictures would have been great.  The prints show the inverter next to the chassis batteries.  But, whether or not we are communicating is not the issue.

 The issue that our members must have correct information and understanding.  A welded, intact ground stud is not the main conductor nor was ever intended to be the conductor of a mechanical joint.  It is the contact areas of the cable ends being held against each other and or the bare metal frame of the chassis that is supposed to be carrying the current. 

Same for any electrical connection.  Yes, there are copper or brass bolts in use for joints, primarily for the positive cables.  Yes, they provide some conductivity, but it is the mechanical joint and the proper contact of the mating surfaces that carries the lion’s share of the current load.

Understanding the above is necessary to properly troubleshoot any electrical connection and we, the staff, have a responsibility to correct any misinformation..

As to your particular configuration where the house bank has no direct connection to a ground via the usual ground stud…I won’t hazard a guess as to why Monaco decided to daisy chain the critical house ground side via a bonded connection inside the inverter.  It may have been done successfully in earlier years, but the majority, if not all the later years in all models is  typically by individual ground studs for both chassis and house directly behind the battery boxes or wherever the batteries are located.  That circuit is what was expected and it was not evident, or at least to me, that the 04 Dynasty had a different circuit until I pulled the prints.

Therefore the issue is not whether you and I have communication issues nor who is “right”.  The issue is to make sure that our members understand the fundamentals of high current distribution so they can troubleshoot properly. Stating that a ground stud was the issue and as in, “not being conductive” is incorrect and we often have to correct such and provide the explanation

You solved the issue….and I have my theories, based on electrical circuity, of where the real problem could have been.  But, many conductivity issues are often resolved by moving and repositioning cables…  and that may have been what you accomplished during your troubleshooting and you will not, and hopefully should not have any further problems.  

Thanks for the feedback and also understanding why the correct explanation of a mechanical electrical joint or connection is necessary….keep us informed….