50 Amp auto reset breaker

[VTSweetpea]

OK- I believe I've found the issue thanks to Chin_k, BobW9 and the rest of you. And I apologize for my ignorance in this troubleshooting. If I had a better understanding of how things were supposed to work electrically, I probably could have reached this point sooner. As my old man was apt to say "If I had brains, I'd be dangerous!"
So I just got back from running a jumper directly from the PD Conv+ terminal (leaving the existing wiring in the terminal) to the positive post on my battery bank. All the coach connections to this post were removed.
I then ran a jumper from the negative battery post (with existing ground connection left in place) to the Conv- terminal on the PD.
I plugged into shore power.
13.7 volts at the Conv+ term of the PD AND 13.7 volts at the battery posts!

So it looks like Chin_k and BobW9 had me on the right track. It appears I have a bad ground somewhere.
Now I have to find it!

[Jlfchinook]

Had grounding problem with my generator, and found it easier to run new ground from generator to frame, might work on charger also.

[chin_k]

Put all the connections back, and run a ground wire from the converter negative to the battery bank negative just to make sure it is all good. A better way to do this is the measure the voltage (potential) from the neg on the battery post and neg on the DC panel. If the grounding is good, there should be very little measurable voltage on the voltmeter, maybe just a few percents... oh... less than a volt definitely. If the grounding is poor along the circuit, then you will see more than a volt of potential between the two points. You can use this to figure out which grounding point(s) is bad without disassembling the connection. Again, a poor connection is just like a shunt (resistor), and you can measure the voltage between the two terminal of a shunt.

[VTSweetpea]

Ran a ground wire from converter neg terminal to battery neg terminal. Charger started charging. Took wire off battery post and connected directly to coach chassis, batteries still charging.
I'm thinking I might do what JLFchinook suggests and just run a new ground to charger.
Anyone know a reason why I shouldn't?

[chin_k]

It will be cheaper if you fixed the ground connection instead of running an additional ground wire directly to the battery. Less connection at the battery post, and easier for the next fellow who end up with your rig if you can keep thing as close to stock as possible. You can add a bigger wire from the converter to the grounding connection for example, but to really have a good effect (lower voltage drop to charge the battery), you need to consider both the ground chassis connection and the red wire that goes around the window to the LVD.

I was in the process of doing the upgrade on the 8 AWG red wire from the converter to the LVD, but I suspended that because I need to go for a quick trip during the Memorial Weekend and have to put thing together. Things always take longer than what I expected.

[VTSweetpea]

Chin_k - I agree but I have no idea where the ground connection for the converter goes or terminates. If it is one of the three ground terminations under the rear of the coach they look intact and tight. So if there is a break in one of them then it's hidden and I don't know how much I can trace to try to find it. I didn't do a voltage drop test on them because my probe wires are too short. I did do a v drop test on the ground in the LVD- from Conv - to LVD - >.10 volt. So I'm thinking the LVD ground is good.
The battery ground termination at the coach appears to be good also since my jumper is attached to the bolt that screws the terminal to the coach.

[chin_k]

For voltage drop test for the grounding, you can do it right by the connectors. scrap the dirt off the chassis, and find a good metal spot near the grounding connectors. Touch the probe on that spot. Then find another good contacting point on the ground connector, e.g., stab into the copper wire strands. The voltage you see is due to the current flowing thru the junction and the resistant of the junction. When the convert is charging the battery, you should see the voltage. If there is no current flow, then you will not see any voltage ( V=I*R ). You should also see the voltage since all the DC appliances use the same grounding connector from the converter too, so you also should see this if you turn on your fridge in DC mode, or turn on the lights, etc.

If you still can't figure it out, you may have to disconnect the connector one-by-one, and see which one killed the flow of electric from the converter, and that will be the one. Then when you re-install the connector, you make sure you do a good job in making a good solid connection.

[VTSweetpea]

Alright chin_k you convinced me to give it a shot. Just to be clear- I don't have to disconnect the chassis grounds at their termination to run this test? I can stick my probe into the end of the wire strands as they sit in the terminal and then my other probe onto clean metal of the frame? Since this is a ground to ground circuit, shouldn't I see less than a volt if the circuit is good? If more than a volt, it's a poor ground right?

[caconcourse]

Alright chin_k you convinced me to give it a shot. Just to be clear- I don't have to disconnect the chassis grounds at their termination to run this test? I can stick my probe into the end of the wire strands as they sit in the terminal and then my other probe onto clean metal of the frame? Since this is a ground to ground circuit, shouldn't I see less than a volt if the circuit is good? If more than a volt, it's a poor ground right?

A better test for continuity is to use the ohmmeter which measures resistance (ohms). If you connect the probes together you will see 0 ohms, indicating a short or perfect connection. If you measure from the wire strands to a clean ground it should show close to 0 ohms if there is a good connection. If it shows a large number, it is a bad connection.

[chin_k]

The ohmmeter will also do the job, but depends on your meter, it may damage it if it is not meant to probe around in a live circuit. It maybe a non-issue since the voltage should be very low, but if you do have a completely bad connection (perfect insulator, which is not the case for you) then you will be pushing full 12 V down the ohmmeter and toast it. This really depends on the design of your meter. The way to avoid that is to disconnect all power when probing around with a ohmmeter. The voltmeter will *require* you to have a flowing current (so if you do find a bad connection, you know it is in the flow path of the electricity). One good thing about using the ohmmeter is that you don't need to do any calculation if you want to know the resistance, but for this case, it is just a "good" and "poor" connection. I would redo the connection if it is anything more than the 0.1 volt, but it is current dependent. ..I would redo the connection if there is any measurable voltage across the connection, really. It should be a nice metal-to-metal connection, and there should be very little resistance since the distance between the two probes is so short.

Take a look at the specification of your multimeter. Some are designed to have a better ohm capability, while some are better for measure milli-volt range. You can do either ohm like Clay suggestion, or do the volt version. There are really many ways to skin a cat.