I was recently helping a fellow troubleshoot the electrics in his motor home. The house batteries would go dead within a couple of days without shore power.

Anyway, the previous owner had added quite a few "improvements" and new circuits. He used the same color wire for everything and labeled nothing. He had not made an as-built drawing for any of the additions and had left lots of disconnected wires hanging in the engine compartment with no insulation or shrink tubing over the bare ends. In short, it was a nightmare to work on.

The trouble was that the charging cable to the house batteries was unhooked and hidden in a rag-tag bundle of wires. There was some sort of isolator device that had been disconnected and never reattached.

The point is that when you make wiring changes you should do yourself and the next owner a favor and throughly document the changes with a narrative and new drawings that you tuck away in your coach files. Different colored wires are essential as are wire numbers, etc. And, unused wiring should be completely removed or at least coiled up and tucked out of the way with some sort of tag that specifies that it is unused. It also helps to include the destination of the wires if they disappear into a harness or firewall.

It's a pleasure to work on a clean orderly compartment and a headache to have to trace and identify circuits that have been hacked over.

I'm not sure when it was implemented, but my Barth has a coach wiring harness that has the intended use of each wire printed all the way down that wire. For instance, the back-up light wire says "backup light" from the front of the coach to the rear.

They even thought to add a few extra wires. When I was adding an electric brake actuator I needed a wire to go from the rear to the front where the actuator resides. I found an unterminated wire in the engine bay labeled "B". I went to the main wiring box up front and there was the other unterminated end of "B". Did a continuity check and sure enough it was the same "B". Brilliant!

Corey

Although Conrad Bennett, the prior owner, did an excellent job documenting the additional wiring he did, Barth didn't.

I got a Fluke Pro 3000 tracer ("toner and probe") from Amazon. Attach the tone generator toa wire, and search with the probe for its location elsewhere.

Corey,

That is absolutely the best it can get. Can you imagine that effort on a SOB mass produced vehicle.

Rusty,

It is imperative that you have a tone generator and a good continuity checker. I have a DMM that works for most functions but the length of the coach makes for some walking.

Spares in the harness, what a concept!!

Don