I know for a fact that there's already a million other threads covering headlights not working but I've looked through every one I can find and tried just about every solution and nothing has worked yet, so here's the issue. I have a 1989 trans am that I have owned for about two years. The passenger side headlight motor works perfectly, however the driver side headlight goes down but won't go up. I have replaced the motor, the plug that goes into the motor, the wiring between it and the headlight control module on the firewall, the control module itself, both wiring connectors that go into it as well as the switch in the dash and nothing has worked. The only thing I have found is that there's a pin missing behind the switch on the dash that controls the headlight motors which I'll try to put a picture of in here. Assuming that the pin must be somewhere I took the dash and the speaker out to look for it but didnt find anything. I know that I have to get a control module from a certain year so I pulled one from a 88 GTA so that's not the problem, and when I use little jumper wires to plug the motors into the plug on the opposite side the driver side works fine but I get the same problem on the passenger side. I'm completely out of ideas so anything will help.

 

Is there a relay for each headlight - one to open & another to close. Maybe I can fine out about that in my shop manuals.

 

On the 1989 system, there are no separate relays, there is the one single module. Nothing at the headlight switch affects one side or the other individually, as per this wiring diagram. The module gets constant +12V and ground, and also +12V on the white wire when the lights are off (door close signal) and on the yellow wire when the lights are on (door open signal).

From the OP's description, I'd be checking the harness to ensure neither wire in the harness that's feeding the driver's side headlight door motor is grounded......

 

Thanks for the advice orangebird but I'm completely confused trying to read that diagram, how would I go about checking for a grounded wire? I ran my own wire from the module to the motor and that didn't work but the colors and number of wires that go from the switch into the dash don't correspond with the ones that go from the firewall into the module (there's 6 that go out of the switch and 5 that go into the module)

 

Well I looked at the diagram longer and I think I see that the two red wires that go out of the module go to fusible links, could one of those be bad and if so where are they and how do I replace them?

 

U should see on the link if it has failed. like burning a fuse.

 

72buickgs I'm sure I'll be able to see it but where do I have to look? The red wires go into the harness and get lost in there, is it just a matter of following them?

 

In the diagram, towards upper left u will see two red wires that attach to blue fusible links. When links fail, they usually get crunchy, cracked, etc. could be a real link of a heavy wire link.
U can but the wire links at most auto supply stores. I do not know the gauge of wire u require. Perhaps someone else can chip in.

 

Yeah I see them on the diagram but where are they on the car

 

I have an '84 T/A. will check location. Not sure we are same electrically.

 

Getting back on track here;

Given the above statement that I quoted, you do not have a fusible link problem. Both headlight door motors MUST be getting power since one works perfectly and the other works, but in only one direction. Since you say you've already replaced the motor, the module, and the module's connector, and since your jumper wire experiment caused the problem to change sides, the next thing that needs to be checked is if one of the wires in the driver's side harness is shorted to ground. Get an Ohmmeter, unplug the door motor's harness from the module and unplug the driver's side motor, and with one of the meter's leads properly grounded to the car, probe the two connections on the harness from the car that leads to to motor with the meter's other probe. Good will be an "Infinite" reading, usually displayed as "OL" on a modern digital meter (OL= Open Line, no connection) , and bad will be any reading of any ohms (indicating that one of the wires is in fact grounded, neither wire is supposed to be at ground potential). Do that test and report back the result.

 

Thanks orangebird, I know I have a multimeter somewhere so I'll look for it next chance I get and try that out.

 

Well I just tried it out and both sides of the plug that goes to the motor said OL, I tried it in a few other spots to make sure it was accurate and it was. So now what

 

Hi RattyTA, Gotta admit I've run out of ideas here. This statement, that you can get the problem to change sides by powering the opposite motors from the opposite sides wiring means the motors themselves are OK, and since you say you changed the module and it's connector I was really hoping the problem was in the harness.

"and when I use little jumper wires to plug the motors into the plug on the opposite side the driver side works fine but I get the same problem on the passenger side."

If I think of anything else you could try I'll post it up, but for now I got nothing......

 

Thanks for all of your help, there's only one piece in the entire system that I haven't replaced which is the plug that connects the motor to the wiring so I might as well throw in the towel and buy that part and if it doesn't solve it oh well.