When I turn on just the parking lights in my 92 bird, the headlight doors flip up. I don't seem to remember this happening unless the headlights were turned on with the parking lights. Is this normal, or is the switch defective? Any help would be appreciated.

 

No, it is not normal for the headlight doors to come up when you have the light switch in the park position. Check the wiring for a short or open somewhere and also check the light switch.

 

Thanks trickster

 

minnvike1
Did you have any success in tracing down this problem? My 91 Formula just started doing the same thing. If you did please post what it is that you found. I'am sure I could trace the problem but with spark chasing you never konw how long it could take. Thanks!

 

Mine's done it twice, bith times replacing the headlight switch fixed the problem.

Chris

 

I changed out the headlight switch and it still does it. Did you ever find your problem?

 

My 91 Trans Am is currently having the same problem. When I turn on just the park light switch, the headlights will pop up (but the headlights are off). I replaced the headlight switch as well as the module that is located on the firewall and it is still malfunctioning. The headlight doors flip up and down without problems, but when I turn off the headlights, the left headlight motor continues to run on (a growling noise) for several seconds even after the headlight is down. I am at a loss as to what is going on... ARRRGGHH! Any help would be appreciated.

 

I never did find out the problem. My headlights are doing exactly what you describe, including the growling noise from the motors long after the lights have completed the closing action. Maybe someone out there has found an answer. I started this post in 2004.

 

Wow, since 2004? If I find out what the problem is and how to fix it, I'll let you know. It's crazy!

 

My '91 Formula is doing the same thing...

 

The gear that pops the headlight motor is in 2 pieces, a nylon piece on the outside, and a metal shaft in the middle, connected at the factory by 3 nylon bushings, which tend to crumble to pieces after a while. See the pic below. These are easily replaced with 3 3/8" ball bearings, so you never have to have this problem again. However, with the popping lights thing, I would start looking for a short somewhere in the wiring.

:edit: However, you may want to be warned that after years of sitting there in the elements, the motor housing may never let go of the gear cover screws due to corrosion, and you might never get the bolts out in one piece. If you do get the bolts out, I would clean the bolts and the holes up real good and use some sort of sealant or lubricant to prevent future corrosion. I've broken 3 housings now due to this problem .

 

The same thing is happening with three of our cars here, so there has to be a common failure. we know it is not the switch as a couple of us have replaced that. We also know that the problem is not with the headlight power wire because the headlights remain off, until the headlight portion of the switch is turned on. Somewhere, the parking light power supply is sending power to the motor although it should not be. What ever is supposed to prevent the power supply from the parking light wire from contacting the motors has sobviously failed. because we all have the same problem..I wonder if it is some sort of relay or resistor that is malfunctioning letting the power through to the motor?

 

Does anyone know if both motors are looped together from one power source, or if each motor recieves it's own hot wire? i guess the first thing i need to do is find where the power supply comes in to the motors and then work backwards to the switch.

 

Don't know about your 91s, but, since I KNOW they have the same motors and relay module, I would assume they are the same as my 87, for which the FSM says the motors are each independently wired with power and ground.

Sounds like you guys have a short near the switch, between the wires for the headlight "on" wire and the park light "on" wire, or at the module for both wires. Or, is it possible that there is some corrosion in the bulkhead connector?

 

Thanks for the info on the motores Maverick. what you say makes sense. I am going to start looking for the short at the module end. If the short was at the switch end between the two power wires, I would think the headlights would come on...but they do not. Unless there is a third power wire that is activated by the switch that powers only the motors going up and down.

 

I replaced the driver's side headlight motor (the one that was running on after the headlight doors were down) and that completely solved my car's problem. Apparently, it was breaking a circuit causing the headlights to pop up after just turning on the park light switch. No more growling noise and running on after the headlights are down, no more headlights popping up when they are not supposed to. Kind of strange, though, because you'd think that the headlight motor was okay since it opened and closed okay but it obviously wasn't. Hope this helps.

 

I'd pull connector #1 off the headlight control module and test the yellow wire and brown wire with a test light. You should see voltage on the brown wire with the park lamps on and voltage on the yellow wire only with the head lights on.
If that checks out, it's a faulty headlight module. Otherwise it's a wiring problem.

Hope this helps.
Lou

 

Come to think of it I had this same problem when I picked up this '91 Formula last May... when you'd turn on the parking light switch the headlights would come up. I got thinking back to '99 or '00 when I got my '91 GTA and it had the same problem. I "rebuilt" the headlight motors with ball bearings and everything was fine with the GTA back then and also with the Formula last year.

Now I'm having another issue with the Formula though... sometimes when turning the headlights on or off the motor will continue to run. Guess I need to pull that assembly out and check the motors out again.

 

Thanks for all the good info on this problem. it's a problem that seems to be common enough that some others will benefit from it.