Headlamp problem....
Thread Starter
Le Mans Master
Joined: Jul 1999
Posts: 5,009
Likes: 38
From: jackson nj
Headlamp problem....
I had my headlamp motors rebuilt (new pellets installed) on my 1994 Vette last week and one headlamp is all messed up...operation wise. The RH light will not go up, but lights, and if I turn it off and manually rotate it open, when I turn on the lights the left one goes up but the right one retracts, and stays lit. So far the motor was disconnected from the headlamp after rotating it up, and upon reconnecting and turning on, it still retracts. Then removing the motor and manually turning in the direction to open the light and reconnecting it to the mechanism of the light, it still retracts, but will not open. The last thing done was to remove the motor from the headlamp assembly and turn on the headlamps and wait for the motor to cycle to a stop. Then open the headlamp assembly and reconnect the motor, which should now be in the "up" position, but when turning on the lights it still retracts. All these attempts were done in an effort to see if the cam on the lamp assembly was in the correct position, and nothing had an effect to letting the headlamp operate fully....even to see if it would cycle in reverse of the LH side. At no point would the RH light go up, and we are out of ideas so I'd appreciate any ideas on how to fix this.
Cruising
Joined: Oct 2017
Posts: 10
Likes: 0
From: McHenry IL
I have a 93 and replaced the nylon bearings and gears in my headlamps. When I re assembled, I got a winking situation. the two lamps would not go up and on together. Perhaps a different problem than yours. But after trying many different things I removed one of the metal housings on the motor itself on the one lamp I thought was out of sync. Or should I say, I didn't fully remove it, I took the two bolts out and rotated the metal housing 180 degrees, bolted it back up and it was back in sync. After looking harder at the housing there was a small flat area that aligned with with wiring harness I didn't notice in disassembly. I did not need to remove the headlamp assembly from the car I did this while it was in place. In my case I attribute this to poor engineering. It would have been very easy to design the housing so it only bolts on one way and not both. I hope this helps.
Last edited by halz93; Nov 25, 2017 at 10:57 AM.
Drifting
Joined: Oct 2015
Posts: 1,674
Likes: 191
From: Shit Creek, USA
I have a 93 and replaced the nylon bearings and gears in my headlamps. When I re assembled, I got a winking situation. the two lamps would not go up and on together. Perhaps a different problem than yours. But after trying many different things I removed one of the metal housings on the motor itself on the one lamp I thought was out of sync. Or should I say, I didn't fully remove it, I took the two bolts out and rotated the metal housing 180 degrees, bolted it back up and it was back in sync. After looking harder at the housing there was a small flat area that aligned with with wiring harness I didn't notice in disassembly. I did not need to remove the headlamp assembly from the car I did this while it was in place. In my case I attribute this to poor engineering. It would have been very easy to design the housing so it only bolts on one way and not both. I hope this helps.
And I can confirm that it is possible to reinstall the assembly 180 degrees out.
Bigger question in my mind is, if you HAD them installed why are you asking here? I'd be asking the person who got it wrong.
Thread Starter
Le Mans Master
Joined: Jul 1999
Posts: 5,009
Likes: 38
From: jackson nj
You state that you know the motor can be installed 180 degrees out, how did you fix that?
Drifting
Joined: Oct 2015
Posts: 1,674
Likes: 191
From: Shit Creek, USA
They don't work on cars this old in their shop, but did me a favor and "jumped" their scheduled work to fit me in. They WILL work on the car to find the problem, but it will be longer to get back in then I'd like to wait, and if it's a simple problem, I'd fix it myself.
You state that you know the motor can be installed 180 degrees out, how did you fix that?
You state that you know the motor can be installed 180 degrees out, how did you fix that?
If I screw something up for a paying customer, their fix becomes job #1. 
I recently installed a reman. motor assembly from a guy on eBay. On reassembly I could see my error on the bench when manually operating the light.
Four bolts and a connector to remove HL assy. Then three bolts and a drift pin to disconnect motor assembly and rotate bucket.
Thread Starter
Le Mans Master
Joined: Jul 1999
Posts: 5,009
Likes: 38
From: jackson nj
I recently installed a reman. motor assembly from a guy on eBay. On reassembly I could see my error on the bench when manually operating the light.
Four bolts and a connector to remove HL assy. Then three bolts and a drift pin to disconnect motor assembly and rotate bucket.
Four bolts and a connector to remove HL assy. Then three bolts and a drift pin to disconnect motor assembly and rotate bucket.
Drifting
Joined: Oct 2015
Posts: 1,674
Likes: 191
From: Shit Creek, USA
The motor was removed and rotated manually 180 degrees but when reconnected, it still did the same thing (which is what I mentioned before). There does not seem to be a way to reinstall the cam that has the roll pin in it, out 180 degrees, and that is where the confusion is coming in. When the motor is disconnected from the headlamp assy and the shaft (where the roll pin goes thru) marked, it turns in both directions when the light switch is turned on. Whether you manually turn the motor to open the headlamp, or rotate it by turning on the headlamp switch and reconnecting it, the headlamp will only rotate to the closed position, and not open. That is why I'm asking about it as nothing can seem to be found as to what to do next...internet or book wise.
Honestly, I have struggled with these pop-ups since buying my '96. It's the reason I got such a good price on it. The Chevy dealer spent a year trying to fix the headlights - to no avail. It killed every potential sale. They wanted it gone.
Two years and lots of head scratching (and $$$) later, and I am learning to cring a little less each time I reach for the switch.
Stanley Miller is the guy who sold me the latest reman on eBay. I'd hit him up for thoughts. His handle is carguy8T8.
I really wish there was a good looking aftermarket fixed headlamp kit for the C4.
Good luck!
Last edited by Renfield; Nov 27, 2017 at 08:15 AM.
