Dbmann

Hi I have a 1988 Mustang GT when I put the headlights on my windshield wipers don't work the high-beam indicator comes on, the gauge lights don't turn on, the dim switch acts all funky the gauges don't work but when the lights aren't on everything works fine.

rmodel65

pull the headlight switch its probably toast and the wires going into it might be damaged(from using the fog lights(they pull too much power thru the thin factory wires)

wbrockstar

I agree with rmodel65. The following link details what needs to be done to retrofit the wiring so it will no longer burn up.
http://www.corral.net/tech/maintenance/foglights.html

I believe this diagram belongs with the write up,but if not I'll edit it out tomorrow.