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No power going into coach??


Woody O
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I checked in the coach today and found the batteries are at 12.0 level. I checked the shore power.  It was normal, but no current was being discharged into coach. Is this a transfer switch problem?

11 minutes ago, Woody O said:

I checked in the coach today and found the batteries are at 12.0 level. I checked the shore power.  It was normal, but no current was being discharged into coach. Is this a transfer switch problem?

I checked the Big Boy. I got 12.3 V on one post and 11.9 V on other post. Looks like this could be my problem. ??? Comments please

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transfer switch is on the 120 vac to feed either shore power or generator to the house breakers and inverter. 12.7 might be the float voltage for the charge on the house. the 11.9 would be low for batteries and if on the chassis, then the method of connecting the two banks is not working. it could be the circuit to energize  the big boy to charge chassis  from house is not working. Not all of the coaches used the big boy for house charging. some have a battery isolator off the alternator and once the chassis is up to a fixed voltage, it charges the house. 

is this a new problem?

is the 120 within the MH working? 

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24 minutes ago, Woody O said:

Correction, 12.7 V not 12.3 V

The green light on the ISO relay is not light. If I push the button on the relay, the light comes on but goes off when i release the button. So, do I need to replace the relay board?

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50 minutes ago, Woody O said:

Correction, 12.7 V not 12.3 V

According to my Progressive Monitor, I have 120 volts coming in , but no current going into coach. "O" draw into coach with nothing turned on.  When I crank the engine, no charge to house batteries. When I crank the Generator, the Air Condition comes on. When I plug to shore, the Air condition comes on. So, it seams I have power to everything except charging the batteries.

Just now, Woody O said:

According to my Progressive Monitor, I have 120 volts coming in , but no current going into coach. "O" draw into coach with nothing turned on.  When I crank the engine, no charge to house batteries. When I crank the Generator, the Air Condition comes on. When I plug to shore, the Air condition comes on. So, it seams I have power to everything except charging the batteries.

The Magnum Energy Panel, which shows the status of the batteries, is showing "power fault" and 12.0 battery level.

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WOODY,

I reread your post....and am sorry, but I am a bit confused.  SO...first things first...

Lets work on the MAGNUM.  You have a FAULT.  NOW> Lets CLEAR IT.  With being plugged into shore or even the GENNY., go to the main 50 amp panel and verify that both 30 amp inverter breakers are ON.  DO the same for the sub panels....all breakers should be ON and NOT tripped.

NEXT......go to the MAGNUM.  Then look at it.  There is probably a pin type circuit breaker.  PUSH IT IN....to make sure it is depressed.

NOW....do a SOFT RESET.  Hold in the button on the front....and wait for about 15 or 20 seconds.  Let off on it or quit pushing.  Go inside.  That should CLEAR the fault.  if you don't know which button to push....google Magnum Soft Reset.  There is a You Tube and also the Magnum instructions.

You MIGHT have to turn ON the Magnum.  If the batteries are LOW....then you should see charging.  The Progressive should be drawing power.  Don't ask me on WHICH side....as your system is different from mine...   

The Microwave lights should be blinking.  If you reset the clock....then put in a cup with water, then turn it on....it should start to heat.  You should see ONE side of the line (1 or 2) drawing amps.

IF the MAGNUM is charging....then you should see high current.  Depending on what the charging level is set to in the remote.....that would be upwards of 100 or so amps.  MAKE A NOTE....learn how to PROGRAM the Magnum remote.  Call them if needed.  DO NOT enable the Search watts function. I recommend, for the age of your inverter, setting the max charging percentage to 80%.....the default is 90 and it may heat up and that is NOT good.  

If all is well....post it.  I wrote a NOVEL on testing the Big Boy.  BUT....I am going to save it and let your report back....read on....

NOW> this needs editing....but read it.....

Just to be clear....are you talking about the BIG BOY that connects the TWO banks to each other or the Salesmen's switch solenoid?  I reread your post and then the comments so I am a little confused.  Look at the PRINT attached.  38070173.  The BIG BOY is the one towards the top in the illustration or layout on the right.  The two Salesman's Switches are the smaller ones in the bottom of that. 

SO....this response is for the BIG BOY....if you measured the voltage on the smaller ones....that is a totally different issue...

PLEASE VERIFY.....The BIG BOY probably has burned or pitted terminals.  There should be less than a few HUNDREDTHS across it.  It is MERELY a switch or contactor that ties the House to the Chassis.  It is ALSO the Solenoid that your Battery Boost switch controls.

If you measure across the REAL BIG BOY....and it is warm to the touch and engaged and maybe humming or you "feel it", then the Voltage across the terminals should be ZERO.....as in NO DROP or maybe a few hundreths....  The way to measure is to find a GOOD GROUND.  Then measure each large terminal to GROUND.  You should have less than or maybe a tenth of a volt....but that would be high.  When the Big BOY is energized....you have the Magnum (or the Alternator if driving) ON and the charging current is going to BOTH.  One side is from the Magnum and the OTHER is from the SHORE.  How driving with the Genny on.....you get charging current from each....and they do NOT fight....they level out.....so you have TWICE the current charging BOTH banks.

Hope this is clear.  I attached a link to a better post....with all sorts of info.  If you had searched, you could have found that and been way ahead.  I also attached a spec sheet on the Big Boy....keep these in your files.

IF all is NOT well.  Report back with what you see and voltages and such.

Good LUCK

 

 

53-00507-100-SERVICE-MANUAL.pdf 38070173 (Schematic, High Current,Low Voltage).pdf

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Not sure if Tom got you your answer. His procedure for checking the voltage drop across the Big Boy is one of the ways you test if it has pulled in. To answer your question of is it the relay or the board, either have someone push the dash switch to combine batteries or use alligator clips ( almost a must have trouble shooting item) from a battery positive to the positive side of the big boy relay coil. connecting this to the ground side of the BB coil will give you a dead short so be sure how u are connecting the jumper correctly. u should hear the internal contacts pull in and go clank. then do the test Tom talked about or measure across the relay to directly measure the voltage drop. it should be very close to zero. If this check out, then the BB is probably working correctly and it could be in the board. The voltage drop may be greater on initial pull in if there is a big difference in voltages between the batteries and the contacts are pitted as the current is high initially and the current will decrease as the voltages between the batteries get closer.  V=I*R ohms law.

Also check the board output voltage going to the BB relay positive coil stud. If it is 12 vdc and the relay has not pulled in or voltages are not equalizing between batteries, the BB could be bad.

I purchased a Klein multimeter with clamp on current probe several years ago from home depot. It gets used at least once a week and once you learn to use it, would help get to the issues with your charging much quicker.

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Frank McElroy and I are in phone communication with Woody.  Thread is not closed, but Woody has a TO DO list and needs to complete that.  Once the problem is isolated, and it is probably an Inverter issue, a write up with specifics will be posted.  Thanks for all the input 

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Good news! The Magnum issue was a really deep issue in that we had to do a "Hard Start".  We had to wait much longer than for a soft start in order to let the stored energy to drain. So, after the "hard start" everything was as it should be. Thank you Tom and Frank for patiently helping me through this. I could not have done it without you two.  First, I thought it was the Big Boy, but Tom convinced me to isolate the problem. Then, it was the inverter. Big bucks! But Tom and Frank had me do a "Hard Start" on the inverter and everything came back up and the batteries are charging !  So, I don't have to replace my inverter! I will report back in a couple of weeks when I get back from my trip as to if still working and then exercise my batteries to determine the SOC of my eight batteries. I now have the manual for my AGM batteries to read up and make sure i do proper battery maintainance. Thanks again Tom and Frank!!

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