I have run into a 2 issues with wiring on my 73' P30 chassis. I noticed a couple of weeks ago that when more than 2 of the 12V interior lights are on at the same time, I get an error on the new Norcold fridge indicating low voltage. This was happening even when plugged into shore power. Also , the more lights on , the dimmer they get. I've got a new house battery. At the time I suspected the original
converter being 43 years old was putting out less than the voltage required by the fridge. Something to look at when I get back from the trip I had planned last week as I have a generator and a battery charger if the converter fails.
So, when we get ready to leave last Thursday, I all of a sudden have no taillights, brake lights, turn signals, or clearance/marker lights. When you turn on the signals, either direction, all of the above come on at the same time. The hazard flasher makes all of them flash at the same time. The headlights function as they should.
I now believe that I may have a chassis to coach body ground issue. Has anyone experienced the same or similar issues and/or have info as to where and how the coaches were grounded to the chassis? I would like to look there first but I haven't a clue where to start.
Thanks,
Mark

It does seem to be a ground problem. These are very common with our old coaches. Unfortunately, with the variation in each coach"s wiring and the many years of corrosion and vibration, there is no telling where the problem is for sure.

OTOH, all grounds are common, ie they all go to the same place, ground. When it comes to ancient vehicle wiring, I save time by running new wires, rather than try to figure out where and how the
old stuff failed.

So, make sure you have a good monster ground from engine to frame to feed the starter. Be sure all your main battery connections are clean. Check/run a ground to your intrument panel and another from frame to taillights. Hopefully that will do it.

I have found 3 variables that seem to be problems for vehicle wiring: age and exposure, poor routing causing chafe, etc and worst of all, poor workmanship on the repairs and modifications done over time. It seems the mysteries of the invisible electrons are too much for many shade-tree mechanics, their attempts at wiring range from scary to almost humorous.

good luck with the electrical gremlins.

I had a problem with the ground on my Barth. It started fine one day, then the next day, it wouldn't start even using the auxiliary battery. My battery terminals just needed cleaning, but I traced the black battery cable out of the battery compartment to where it was bolted to the frame, and cleaned the end of the cable and the frame and reattached it. There was another grounding strap attached to the lower left side of the engine, that was bolted to the frame. I removed that one also, and cleaned it and reattached it. Since then, I haven't had any problems.

Bingo!