Headlight bulb harness is melting. Ground Side. The plastic clip itself on the inside is melting where the metal prong from the bulb touches it. I've gone through 2 harness and it still does this. Could it be my bulbs? Maybe the prong is misaligned? Not sure. It is grounded with a 12 guage wire directly to frame also.

 

I'd blame the bulbs.
that's the only time I've heard of a harness melting

 

if you are running high wattage bulbs it will do this.