joseo91

I have a 92 Convertible 5.0 and everytime i turn off the car and the headlights are left on the headlight switch goes through the roof. Temp is fine and not overheating. Not a headgasket problem. Any body having the same symptoms? I"ve heard to replace the headlight switch.

kennebellgt

headlight switch goes through the roof? makes no sense.

93_5.0_gt

sounds as if you have a shorted out ground wire. the temp sender wire is a white wire with red stripe(<< i think)that if it grounds fully to something, your gauge will do that. try a manual gauge and see what its actually running at

joseo91

Should I run a new wire and solder it to the wiring harness to instrument cluster because it would be hell to track that short to ground. it says the sender grounds to the engine and has the Red/white wire going to the instrument cluster A3 pin. If it where shorting to ground wouldn't the temp go down? IF it were being triggered like it is when the illumination of the headlight switch then it would be a short to power causing the temp gauge to go up like it is.

steve r

If you leave your headlights on when the car is off, in alot of fox mustangs the tempgauge will rise up, then when you turn them off it will go back down

Blckstng93

My temp gauge goes up when i turn the lights on but goes back down when the lights are off. Havent been able to figure it out for months.

ttocs

seems like an easy enough fix, turn off your lights when you turn off your car........

joseo91

Seems simple but a bit of a problem if your driving at night like I am and it happens. I"m going to just an autometer gauge. The stock ones are unreliable anyway.

brentloftis

Replace the headlight switch, 30 bucks at most part stores. The other option is to use the switch to activate a relay and have the lights powered directly from the battery rather than running the current through the switch.

joseo91

Yeah I was going to do that today because the factory wire gauge they used is too small.