'86 Sunrader Electrical Issues

[hddols]

I just replaced the coach battery on my '86 Sunrader - I had the wiring bundles marked for + & -. After this the alternator will not function / charge (engine runs on battery alone) and I can't get any coach battery power to the camper. Both engine & coach batteries are good - 110 Hookup / Converter still works fine - along with all interior wiring - I'm not sure if the isolator went bad - or the alternator - or both -- or something else - such as a mixed up wiring on the coach battery connection -- if this was the case what could I have been damage?. Any suggestions would be most helpful - thanks. One note - the Charge Light would always come on and stay on when the engine was started until I revved up the RMP's abit - then would go off - now it's on full time regardless.

[Vanman]

I would start by removing all the coach battery wires, after labeling them each with a number and +/- that you think is correct .
Then see what happens, what works and what doesn't. If everything is OK next start to check coach battery wires one by one.
Hopefully just a bad connection or misconnected wire. If lots of wires involved keep a list of what's what. Take your time, be careful, write it all down.

Might want to check tightness and condition of alternator belt first.

[Terry406]

I'm trying to figure out the wiring in the coach battery compartment of a 86 Sunrader. When I bought it, it didn't have a coach battery installed. I just bought a deep cycle RV battery, There's 5 wires with ring connectors, 3 white and 2 black in the coach battery compartment. So far, I've determined that one white is ground, because it bolts to the chassis on the other side of the propane tank. 2 black are positive. 1 black wire is reading 7 vdc when I touch ground with the other lead of my meter. So, I know that connects to the positive terminal of the coach battery.(Obviously, at the manufacturer, they didn't care which color wires they used for positive and negative.) The other black wires goes up to the isolator on the firewall under the hood. It's a two connection isolator, a red wire coming off the other side of the isolator has been cut and went to nothing. I connected it to keyed power, so I know that has to go to the positive post on the coach battery. As for the other two white wires, one has +12vdc when 110 AC is plugged into the converter when I measure it on my vom, with the other terminal of the meter touching ground. So I know that white wire goes to the positive side of the coach battery. I tried to follow the other and last white wire, and I've lost it up on top of the gas tank in the harness. There's another two connection plug coming out of the harness up near the top of the gas tank that's plugged in to nothing. I've recently installed a new gas tank and new fuel pump inside of the gas tank. When I had the gas tank down and doing that work, I know the fuel pump is wired up correctly, and that plug didn't go to that fuel pump at all. I'm thinking maybe the back water pump near the water tanks to pump water to the shower and the sinks etc. Is where that wire is supposed to plug into coming out of the harness, but neither of the two wires coming out of the harness with that plug on it are white. I can't find any other plug anywhere down there where that plug might plug into. So I've lost the white wire coming out of the coach battery compartment into the harness up near the gas tank. It doesn't have any continuity to ground, so I'm guessing it has to go to the positive terminal of the coach battery. I just want to be 100% sure when I hook the coach battery up to all of the 5 wires. So if my assumptions are correct, there would be five wires in total, four going to the positive terminal, and one going to the ground terminal of the coach battery. So my question is, does anybody know where that other white wire going into the harness by the gas tank goes to? And where is the water tank water pump? How is it wired? And where that mystery plug up near the top of the gas tank coming out of the harness goes to? And am I correct, two black wires two white wires going to positive terminal on Coach battery? And one ground white wire to the negative terminal on the coach battery? Any help would be greatly appreciated.

[Terry406]

P.S. I just went down and bought five 30 amp inline fuses that I'm going to wire up to the five existing wires in the coach battery compartment before I attach any of them to the new coach battery. So if I have anything incorrect, I should blow a fuse before I would hurt any accessory, or worse yet, melt any wires. But any help with the five wires in the coach battery compartment, two black and three white, would certainly be much appreciated, if anybody knows or has any of the same kind of setup, please let me know. Thank you very much...

[Terry406]

I'm sorry to keep posting, one more thing, where I'm plugged into 110 shore power, I keep popping the GFI breaker on the 110 outlet I'm plugged into. Sometimes with nothing plugged in at all inside of the camper, and sometimes when I run the roof air conditioner for a few hours, especially overnight it'll pop the GFI breaker on the 110 outlet that I'm plugged into. Just thought I would throw that out there because that's just another mystery! I would really appreciate some input from somebody that might have same or similar issues.

[WME]

 T, just reading your 3 posts gave me a headache. You seem to be a victim of the curse of an old RV,  a rabid previous owner 😱. I'll try to help starting with very basic steps so stay with me.

Wiring color codes 110v AC,  green/bare wire ground, white neutral, black hot.

12v DC under the hood. red +, black -.  12v DC in the RV  black +, white - (ground) Any red wire in the RV 12v section is most likely a PO addition so watch out for them.

Look at the wires on your battery are they stranded? Are ANY of them solid wire? (bad) 

Things to actually do, in addition to a volt meter you need a AC polarity checker.

Use the checker on the shore power to verify it's OK. Then with the RV plugged in check  each outlet to make sure it's correct. Then CAREFULLY use the voltmeter to check for stray voltage between a shore power ground and the frame of the RV. Folks on damp conditions and bare feet have been zapped steeping on the metal step.

All good? Then hook up the black wires to the +battery, then hook up 1 white wire at a time until all of them are on the - terminal. Big sparks or smoke stop, un hook wire🤪

Report findings

 

 

 

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[Maineah]

If the GFI is tripping the GFI is a AC issue. Nothing battery powered light's, fans etc. If you have things plugged in unplug them all of them, plug the camper back in and what happens. If the GFI doesn't trip plug them in one at a time. The AC is line powered and fridge possibly is too make sure they are off. It is possible  your converter can cause tripping but only on the AC side.  Older GFI were finicky and had a lot off tripping issues if all else fails replace it they are cheap. Coach wiring color is not industry standard you might find any thing. Usually white is ground black is + it's more common but you can't count on it. My Nova Star + was blue and ground was green.