Would follow-up whatever Gilly suggests, he's the pro. However, by the way, a "bad wiring harness" can sometimes just mean a bad ground. Sometimes it's simply a matter of regrounding that part of the wiring system (for example, a grounding point somewhere that's gone bad and regrounding the questionable components to another new ground).

I'd also check the fuses for the indicators going bad (turn signal, etc) to see if one is going bad and cutting-power intermittently.