joseph p

Within the last year and a half I have taken both headlight motors apart on my '89 coupe and replaced those three nylon barrels in each. Both times it solved the problem. Now my pass. headlight won't come up.
Could it be the same thing? I do remember a couple of weeks ago that the headlight door had ice on it and wouldn't come up until I cleared it. But I think I used the headlights since then...???
Any ideas?
Thanks

jfb

If your 89 has headlight relays, check the relay for that headlight. You can swap relays to see if the problem follows the relay. Also, you can check the headlight motor by unplugging it and jumping 12v from the battery to the headlight motor to force it to run.

joseph p

I cranked it up by hand. When I turn off the lights it goes down...but then it won't go back up by itself.
????????

*89x2*

Replace the delrin bushings -

joseph p

Could I have installed them wrong? One year's use? Worked fine after repair.
Thanks

jfb

I don't know what year the C4's went to an electronic switch for the headlight motors, but if you have relays, there are three relays, one for each side and an additional one for making the right door to go down. If you will swap the two headlight door relays (not the isolation relay) and the left headlight won't go up, then the trouble is the relay which isn't expensive. This is an easy test, give it a try!

ElisTwoCents

Welcome to the club buddy!

Check the relays and try the manual crank, my gears go out often on the right headlight (3 times in the last 4 years)

Demonic85

What if the headlights go up, but one motor continues to run after the headlights are up and working?

onedef92

Sounds like your bushings to me. Most headlight woes on 1988-96 Vettes are due to worn bushings.

VetNutJim

I think there were no more relays after the 84 model year.
The 84 had a three wire motor circuit and limit switches, I believe.

The newer system has TWO WIRE motors with no limit switches to report the position of the transport assembly.
The newer system uses a Headlight Control Module mounted on the left front wheelhouse.
There is a CURRENT SENSE circuit in the module that senses when the lights are open or closed by the increased current draw of the electric motors.

It's a 'stereo" (two channel) sensor and either side can fail and affect the operation of it's respective motor.

If the motors are NOT running replace the module. If the motors ARE running but the assembly is not moving properly check the gears and mechanical assembly.

Demonic85

When I turn them on, they both operate normally, both headlights work. However, on the driver side, the motor continues to run even though the headlight is up. It does it when I close them too. If I pull the **** out just slightly when they're closed, the motor shuts off. Its an '85 and there are no bushings to replace, it has 2 gears.

rodj

think there were no more relays after the 84 model year.

On my cars the "87 still has the relay the '89 and '90 are electronic