If you make changes to wiring (or anything else) DOCUMENT THE CHANGES ! , draw schematics, take pix, make notes in the manuals of what you did , why you did it, when you did it, and keep ALL the documentation together .
Makes it easier to change back if needed, both for you and the next owner .
Boy, THAT is a fact, and excellent advice! The '88 Winnie we recently bought was far "cleaner" of "amateur re-engineering" than most in the wiring department - but even at that, there was enough to be a pain! The headlights only operated on low beam, the turn signal stalk switch normally used to dim the lights had apparently failed, and instead of replacing it properly, a former owner had simply massacred the wiring so that when the headlights were turned on, only the low beams were active.
I ended up completely re-wiring the headlights, using #10 wire thru relays direct to the battery, and switched by a new dash mounted dimmer switch, and wired so that in the hi-beam setting, both hi AND lo beams are operating - the lights are better now than when the MH was new. The windshield washer didn't work - someone had also butchered that as well, so had to fix it. Someone had installed a newer dash radio with cassette player - and even though the MH has nice front and rear stereo speakers, whoever wired the newer radio has wired ALL the speakers in series - and the impedance mismatch creates severe distortion, not to mention the lack of proper front/rear fader and stereo isolation.
BUT, in looking at older MH's, ours is FAR better than most in the "owner improved", butchered wiring department - but I suppose in the eyes of some, I am also guilty of "amateur re-engineering" of the electrical system!