headlight question
Thread Starter
Burning Brakes
Joined: Aug 2002
Posts: 1,190
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From: Milan Indiana
headlight question
working on an 85 and looking for help with headlights. when i turn light switch,lights come on but doors dont open.If i manually open them,when i turn switch off,the headlights flip back to closed.any ideas why? i dont have access to schematic to check wiring but on each side there is an open plug(oval shaped with 2 plug ins) but there is not a matching part to plug them in. trying to find a c4 to look at or if someone can fax me a schematic i would greatly apreciate it. thanks Paul
Team Owner
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From: Fort Knox, KY
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I don't have the schematics for an 85, either. But it sounds like a headlight relay issue. Check that first.
The 1984-87 C4 headlights have a plastic driver gear in the motors. The plastic gear is driven by a steel worm gear, needless to say metal against plastic equals trouble.
One other issue for 1988-96 models is the plastic gear is fitted on the underside with Delrin bushings from the factory. These bushings turn to powder over time and the gear will free spin.
Either way, you can get replacement gears and the bushings through the aftermarket Vette catalogs, some auto parts stores and Home Depot. You have to completely remove the head lamp door to get the motor out.
Click this link for removal process.
http://corvettefever.com/howto/33098/
Hope this helps, Good Luck
The 1984-87 C4 headlights have a plastic driver gear in the motors. The plastic gear is driven by a steel worm gear, needless to say metal against plastic equals trouble.
One other issue for 1988-96 models is the plastic gear is fitted on the underside with Delrin bushings from the factory. These bushings turn to powder over time and the gear will free spin.
Either way, you can get replacement gears and the bushings through the aftermarket Vette catalogs, some auto parts stores and Home Depot. You have to completely remove the head lamp door to get the motor out.
Click this link for removal process.
http://corvettefever.com/howto/33098/
Hope this helps, Good Luck
Team Owner
Joined: Mar 2001
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From: Cincinnati, Oh USA
Unplug the headlight motors and jump 12v to them and see if they open. If not, the trouble is in the motor, if they do, then you have defective relays. Motor problem is most likely the contacts that make connection at the end of the door travel which set the motor up to open when the headlight switch is turned on. These contacts wear out. You need to take the motor off the car and open the case up to inspect the condition of the contacts. There are two sets of contacts, a pair on each end of the motor, one for opening, one for closing.
Last edited by jfb; Feb 28, 2006 at 03:21 PM.
Team Owner
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From: Fort Knox, KY
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Originally Posted by jfb
Unplug the headlight motors and jump 12v to them and see if they open. If not, the trouble is in the motor, if they do, then you have defective relays. Motor problem is most likely the contacts the make connection at the end of the door travel which set the motor up to open when the headlight switch is turned on. These contacts wear out. You need to take the motor off the car and open the case up to inspect the condition of the contacts. There are two sets of contacts.
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Originally Posted by pnewt
thanks guys, will check all of this out. appreciate the info Paul
http://www.tabercorvetteparts.com
They have good prices and merchandise selection. I've always been satisfied with 'em.
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Pro
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From: Santee Ca
If I remember correctly there are two headlight relays on the left side of the car mounted to the front tire wheel well. I think they have a cover bolted over the top of them. If you swap the relays and the lights open but don't close then you need a new relay.
Thread Starter
Burning Brakes
Joined: Aug 2002
Posts: 1,190
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From: Milan Indiana
headlight doors
great info guys. agent 66, i guess i should keep the assembly manuals when i sell a car-so i dont have to bother everybody!!! (had a 90 ZR1 with these pages) thanks again Paul
Melting Slicks
Joined: Jul 2003
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From: Reno/Sparks Nevada
Have you tried manually opening them with the lights on? If you have the lights on and you try to manually open them and they immediately operate and open, then I would think the problem is in the motor brush and/or limit switches. After time the switch contacts/brushes and armature get gunked up. If the motor turns when your trying to rotate them manually then the relay is putting 12volts to the motor. You mentioned that they go down when you turn off the lights, so that part of the electrical systemis working. If you look a the schematic you can see there are relays and limit switches that make this system operate. Dismantling the motors and cleaning them up extends their life considerably if the problem is in the motor. If you need more help on troubleshooting the relay system, pm me and I can reply by email.
Also, if your headlights are closing then the wiring is intact. The extra plug you're finding might be for the hood lights. Many times they are disconnected because they kill the battery when the hood is left open for some time.
Art
Also, if your headlights are closing then the wiring is intact. The extra plug you're finding might be for the hood lights. Many times they are disconnected because they kill the battery when the hood is left open for some time.
Art
Last edited by MrRenoman; Mar 1, 2006 at 08:20 PM.
