I started up my 1990 GXL Coupe and for some reason the headlights would come on but the motors would not go down when i turn my switch on and off.Left the battery plugged up and tried other switches from earlier models and no luck.The next evening I started up the car with the lights on using the original switch which if you pushed on the wiring in the back of the switch the dash lights would go out.I ran the car for about 5 minutes then the check engine light came on and then the car didnt want to go anywhere would try to stall out.Once i turned the car off I disconnected the battry because i could smell something plastic like burning and could see a little smoke under the car.When i smelled towards the ECU that is where it smelled the worst.I pulled the ECU and found that Two things had burnt up.What could have caused this could it be the headlight motors shorted something or the switch did or maybe neither.All i know is that the dealer wants 1000.00 for a new one and I am afraid to plus it into the car it might fry that one to risky without knowing.Is there a diagram of the ecu where i can see what controls what on the boards themselve.Sorry to be so long but wanted to get it all out there.Please Hel p ME

 

The ECU and headlights switch have nothing incommon.

Are you sure it was the ECU found under the carpet/firewall area under the passengers feet?

 

im with icemark
it couldnt have been the ecu

 

Then something else burnt the ECU how could i figure out what caused it.It is under the passenger floor.Something burnt it up good

 

To burn up a ECU you have to have something wired very wrong. Something more than just turning on the lights... what have you done recently to the car?

Its fused on its power circuits and there are resistors on most of the inputs to act as buffers.

This is the box under the floor panel against the fire wall on the passengers side of the car right? Probably says N375 or N350 or something like that on the top?