I'm replacing the gear on my driver side headlight motor since it spins with no result. The passenger side works fine. I recently replaced that h/l motor with a used one but the plug in harness attached to the main car wire loom didn't work. I already knew this but I further confirmed a bad motor as well, by running jumper wires to the connector on the passenger side before purchasing the used unit, which worked under the same test. The used unit spun for a week before what was left of the gear quickly toasted, and now spins indefinitely. My headlights still light up but now neither spin up, though the one on the passenger side should since it has no issues.

My question: Is there a relay(s) somewhere that is shot? Both headlights run from their respective connectors back to the driver side into a small black box mounted on the fenderwell. It seemed odd to me that initially one headlight worked, motor and light, while the other just lit up, when both wire harnesses run into the same box. Is this box shot? If it has relays for the headlights, where would they be and how can I test them? There are no blown fuses, it's a 1988 Vette.

I'm replacing the gear on my driver side headlight motor since it spins with no result. The passenger side works fine. I recently replaced that h/l motor with a used one but the plug in harness attached to the main car wire loom didn't work. I already knew this but I further confirmed a bad motor as well, by running jumper wires to the connector on the passenger side before purchasing the used unit, which worked under the same test. The used unit spun for a week before what was left of the gear quickly toasted, and now spins indefinitely. My headlights still light up but now neither spin up, though the one on the passenger side should since it has no issues.

My question: Is there a relay(s) somewhere that is shot? Both headlights run from their respective connectors back to the driver side into a small black box mounted on the fenderwell. It seemed odd to me that initially one headlight worked, motor and light, while the other just lit up, when both wire harnesses run into the same box. Is this box shot? If it has relays for the headlights, where would they be and how can I test them? There are no blown fuses, it's a 1988 Vette.

That black box you found is the headlight control module. You will need an FSM to troubleshoot it.
ps--They aren't cheap, get your wallet out.

That black box you found is the headlight control module. You will need an FSM to troubleshoot it.
ps--They aren't cheap, get your wallet out.

Can I bypass this for now by wiring it to the fog lights with quick connectors or will this mess something up? It seems if they need power to turn then this would be alright, but I don't know for sure. Or wire it to something else?

Can I bypass this for now by wiring it to the fog lights with quick connectors or will this mess something up? It seems if they need power to turn then this would be alright, but I don't know for sure. Or wire it to something else?

I would not do that. Are you saying you are not getting power to either headlight motor? Or are the motors running but the headlights not moving?

I would not do that. Are you saying you are not getting power to either headlight motor? Or are the motors running but the headlights not moving?

I have the ability to turn the headlights on and they light up fine, so that half of the relay works, but neither motor does anything at all now. I know both motors are good now which lead me in the direction of the relay. I'm guessing that inside the black box that says 'guide' on it, is two separate relays for each motor, and their probably both shot now. Your right, that part is pricey to replace.

Does the '88 have 2 or 3 wire hookup to motors?

The lamps themselves run independent of the box; it only operates the motors by electronically reversing the polarity of the feed; hense 2 wires.It is solid state and not repairable
The early style had 3 relays under a cover and 3 wires to each motor ; a forward / reverse wire and a common.
Bottom line is; you can manually wind the doors open and lamps will operate as normal without the box/ relays hooked up

Does the '88 have 2 or 3 wire hookup to motors?

The lamps themselves run independent of the box; it only operates the motors by electronically reversing the polarity of the feed; hense 2 wires.It is solid state and not repairable
The early style had 3 relays under a cover and 3 wires to each motor ; a forward / reverse wire and a common.
Bottom line is; you can manually wind the doors open and lamps will operate as normal without the box/ relays hooked up

It's the two wire motor. My reason for bypassing it somehow is because I need to title and register the car and it has to pass an inspection...I already got gigged for it not coming up even though it lights up and I used that exact statement that 'I can manually raise it' and they said 'nope, sorry'. I may just wire it to a toggle switch and relay for now and trace all this down later. I was curious as to whether I could wire it to something that already works, in relation to headlights ie: foglight wires, to get it to pass for now. Toggle switch may be my route.

It's the two wire motor. My reason for bypassing it somehow is because I need to title and register the car and it has to pass an inspection...I already got gigged for it not coming up even though it lights up and I used that exact statement that 'I can manually raise it' and they said 'nope, sorry'. I may just wire it to a toggle switch and relay for now and trace all this down later. I was curious as to whether I could wire it to something that already works, in relation to headlights ie: foglight wires, to get it to pass for now. Toggle switch may be my route.

That will be ugly! You will need a double throw, intermittent, polarity reversing switch. Why don't you just check around for a used module before you butcher the wiring in your car?

That will be ugly! You will need a double throw, intermittent, polarity reversing switch. Why don't you just check around for a used module before you butcher the wiring in your car?

Alright, you've convinced me. I'll see if I can't find a used one, or just break down and buy a new part. Any good recommendations as to websites that might be good for both new and used?

Alright, you've convinced me. I'll see if I can't find a used one, or just break down and buy a new part. Any good recommendations as to websites that might be good for both new and used?

For used try vette2vette.com or call Chris @ 770-
546=3504. For new I would guess your local dealer (if GM didn't shut them down that is).

It's the two wire motor. My reason for bypassing it somehow is because I need to title and register the car and it has to pass an inspection...I already got gigged for it not coming up even though it lights up and I used that exact statement that 'I can manually raise it' and they said 'nope, sorry'. I may just wire it to a toggle switch and relay for now and trace all this down later. I was curious as to whether I could wire it to something that already works, in relation to headlights ie: foglight wires, to get it to pass for now. Toggle switch may be my route.
A power window switch would work and easy to wire up. But you will need a left and right headlight motor switch.
David

A power window switch would work and easy to wire up. But you will need a left and right headlight motor switch.
David

That sounds interesting, but when I think of my overall objective to restore this car, I have to agree that I would be better served just to find a replacement actuator then start hacking.