Just bought my first C4 & don't know a thing about them yet. I have 3 C3s so I know lots about vacumn operated stuff. I just bought an 87 convertable with 29 K miles on it. Everything seems to work except the passenger side headlight does'nt go up. Is there a troubleshooting guide somewhere or can anyone tell me where to start ? This forum has kept me & my C3s going for along time now but this C4 is a whole new world to me. Thanks to anyone who can help !

 

first check to see if you can hear the headlight motor running when you raise and lower the lights. If you can hear the motor, chances are you have worn plastic bushings or stripped plastic gear. Easy DIY job, but takes a little time and patience.

Here's a decent article on repairing C4 headlight:

http://www.corvettefever.com/howto/33098/index.html

OK, '87 does not have the bushings, only plastic gear:

http://ecklers.com/product.asp?pf_id=39975&dept_id=1477

 

If so use the manual know atop the motor to see if you can move the motor. If it feels sloppy and takes many turns before you see any motion or no motion at all you just need to replace the three small plastic bushings inside the gear case.

 

found this in C4 sticky note repair section:

84 - 87 Headlight Motor Repair.

Just a few notes about my experience with the earlier model years. As stated above the 88-96 motors had bushings which could be replaced. In the 84 - 87 MY they had no bushings. JHammons and I did some PMing back and forth and what we both found was that once the headlight was disassembled from the car and the motor was disassembled there were two gears that worked the motor. A large white gear which actually gets turned by the motor and a small black gear that the white gear turns which allows the headlight to move.

JHammons and I found my condition of the motor running but the headlight not moving all the way through it's cycle was caused by a white gear tooth failure. A quick order of a $23 large white gear from ZIP Products and some time breaking into the motor and everything worked perfectly. It seems to me that it's very rare that both headlights won't move at the same time so I took apart the motor of my good headlight and did some camparisons on how everything falls together. An hour and a half or so and everything is fixed and works perfectly.

And if you have electrical issue, I "borrowed" this from Agent 86:

http://members.shaw.ca/dankai/Headlight%20Doors.pdf

 

Thanks for the link Mike. That will be very helpful. I just tried to turn the manual **** on the motor and it does not turn. The **** on the working light turns fine. I don't think I should take a pliers to it. I'm guessing if it is froze up or stuck for some reason, the fuse link might be toast for that headlight. What do you think ?

 

unhook the power to the motor and see if it turns.

Then take apart the Light swivel assembly to see if it is locking it up. The assembly is really hokie if you examine it.....not a bearing or anything..

 

No pliers. At this point, it's anybodys guess until you disassmble the gear housing in the motor. Best case, the nylon gears are locked together, worst case, the motor has seized up.

 

Thanks guys, I can't do it today but I'll pull the bucket out & put it on the bench & disassemble it As soon as I have time. I'll let you know what I find. Thanks again

 

OK guys.....I checked my red leads to the relays & had power there so the fuse links were OK. So I removed the bucket & put it on the bench. With a little wiggling on it I got the manual **** to turn. I took the bucket & pluged it in on the drivers side & it opened. Ya Hoo...... I reinstalled it, pluged it in & it works. Alls well........Thanks for your input everybody !