50 Amp auto reset breaker

[VTSweetpea]

OK Chin_k just did your recommended test. Voltage reading from all 3 grounding lugs to bare metal on the chassis was 0. That was done with pushing the probe into the strands of each ground wire as best I could. Coach was plugged into shore power at the time. Reading 12.5 volts at the converter and at the batts.
I then ran a wire from the converter neg terminal and clamped it to the chassis. Voltage at the batts and the converter jumped to 13.5 volts.
To be blunt, not sure what the hell is going on. Altho I appreciate your help as well as all the other people who chimed in to try to help me track this down, I'm at the point of frustration now. If running a new ground wire gets things working again, then so be it.

[chin_k]

Were you doing the test while the converter on shore power, and DC appliance is running? I would turn on the fridge on the DC mode since it can really suck up the power.

If you do not measure any appreciable voltage across the junction, then change mode on the meter to ohm and see if you have a good connectivity across the connection. If you see that it is a short (it should not, unless you were probing area with think oxide or paint/oil), then whatever you did do not count.

One thing that maybe helpful to you is to see if anyone know exactly where the converter's ground is attached to the chassis, and how the battery negative is attached to the chassis. I think there is a diagram on the manual that shows that, and in most cases (with exceptions like mine... still can't find the breaker for the genset...) it is accurate. This way, you can concentrate on one specific connection. I may also disconnect the connector, attach a wire to it, and see if the output from it to the battery changes compare to connection to the battery via the chassis. You know at this point that the only difference is the path from the converter to the battery, and there is no device between them other than wire, chassis, and wire. No need to deal with LVD or the PD4645, since they are all good.

[caconcourse]

OK Chin_k just did your recommended test. Voltage reading from all 3 grounding lugs to bare metal on the chassis was 0. That was done with pushing the probe into the strands of each ground wire as best I could. Coach was plugged into shore power at the time. Reading 12.5 volts at the converter and at the batts.
I then ran a wire from the converter neg terminal and clamped it to the chassis. Voltage at the batts and the converter jumped to 13.5 volts.
To be blunt, not sure what the hell is going on. Altho I appreciate your help as well as all the other people who chimed in to try to help me track this down, I'm at the point of frustration now. If running a new ground wire gets things working again, then so be it.

The ground lug assignments are shown in the Chinook sub-floor diagram in the owner's manual, figure 9.3 in the copy I viewed. The 12V distribution ground is shown as the middle lug in the three grounds in the driver side rear set at the rear of the frame (above the black water tank) although I suspect it could be any of the three if the installer was not careful to line them up. It should be a simple check to show 0 ohms between those three wires and the frame, or maybe a good idea to recondition all three connections by removing them, buffing the lugs and wires and reconnecting.

The battery negative ground lug in the same diagram is shown on the frame very close to the 50amp reset breaker you replaced. It too should show a zero ohm connection to the frame. I can't imagine that ground being open or almost no 12V circuitry would work, including battery charging from the alternator, but that's the only other ground connection in your broken circuit.

If the ground lugs have a solid connection to the frame, then there may be a break in the wire from the DC card to the ground lug. You can test the wire by doing an ohm meter check from the brown box end to the ground lug (just use a long jumper cable to get to the far end to the meter.
Running a new ground wire would fix the problem in any case, but if the old wire is not broken somewhere in the middle, you should be able to reuse it with a good re-termination, which seems like less work.

[VTSweetpea]

Epilogue- the issue of the house battery bank not charging is resolved! It was the ground wire for the 12 volt system located on the rear driver side of the chassis as shown on diagram 9.3 of the owners manual. Special thanks to Chin_k and Caconcourse for sticking with me as I dealt with this problem.
I have to admit that altho I had determined that my issue was a poor or bad ground, I was going around in circles in trying to locate it. For some reason, I was focusing only on the ground connections located by the battery compartment and under the generator compartment. Then my wife (she's VTSweetpea) read all the responses on this forum and asked me if I had looked at the grounds on the other side of the rear chassis. She said Caconcourse among others had mentioned it and even referred to Diagram 9.3 of the OM. That brought me out of my tunnel vision! I went under the coach and checked the grounds there. Sure enough, there was one dangling in the wind! The bolt attaching the ground lug to the frame had corroded and sheared off. 45 minutes later, new lug installed and ground wire reattached. PD charging batteries at 13.6 volts. Hallelujah!
Moral of this story- Read all of the helpful suggestions at least twice, then have your wife read them to make sure you didn't miss something!

[chin_k]

Glad that you got this resolved.

I bet if I did not come in and confused you, you would have got this resolved in half the time

(BTW, our better-halves usually deserve more credit, but don't drill on this too much in case they want to watch over us all the time.)