bolowbc

Hi there,

I have read the complete headlight rebuilt FAQ.

The issue I am having is that the motor for my passenger headlight keeps working after it has closed/opened all the way. There are no problems with opening/closing, it just spins an extra 5 seconds or so.

The dealer says one of the gear teeth is broken, which explains the ratcheting movement as the motor tries to turn the headlight beyond the stop points. However, because the headlights open/close smoothly, I'm thinking the broken tooth might have been caused by an electrical problem.

To my knowledge, the later model (1995) headlights do not have relays, so I'm thinking perhaps the headlight control module (square black piece) needs to be replaced?

I have ordered a bronze gear/bushing rebuilt set anyway, but I can save some time if this is not the problem.

Input is greatly appreciated.

Cheers,
Will

jeffp1167

when you replace the bushings that gear comes out anyways so either way it takes no more time to do gear replacement over bushing replacement.

on my firebird it headlight motors ran for say a extra 10 seconds and its bushings were the cause. If both motors work then that control box isnt the problem.

jimg's'93

It's the bushings.

MikeC4

Yep, there are 3 nylon bushings that sit inside the gear. These bushings turn to dust over the years. When the bushings go out, the symptoms are just as you describe, a run on of the motor for approx. 5 seconds. Thankfully, GM designers put a "timer" on the motor operation, so that it wouldn't run continually if there was failure due to bushings or stripped gear.....You can buy these bushings at Autozone, Pep Boys or Advance Auto in the "Help" section. Just make sure you buy the solid bushings, and not the hollowed out ones. One of the C4's I owned had the hollowed out bushings installed by previous owner and all 3 of them "collapsed", and I had the same kind of problem as you..

Easy and cheap fix( a little daunting the first time, but once you have done one, you'll be an expert)....

EDIT: The bronze gear is overkill, as the nylon gear rarely goes bad. You are correct in your observation that the gear is fine since the headlight goes up and down without a problem. You could have fixed your problem for $5 bushings instead of paying all that money for the bronze unit.

bolowbc

Awesome, thanks for the replies guys.

Yes, someone had posted in the headlight rebuild thread that the bronze gear is overkill as well. I figured if the gear is bad, I might as well swap it.

I guess I'll find out when I open it up... if gear is good I'll just return the unit.

MikeC4

just to give you an idea of my experience, I have repaired 8 C4 headlight motors and 2 C5 motors, and the culprit on ALL of them where the nylon bushings. GM chose nylon bushings to "absorb" the noise or "clank" that would be associated when the headlights hit the point of full up or full down position......a shock absorber if you will.....( I am not a mechanic, but I do seem to buy/sell/buy/sell C4's as a hobby)

(HINT: be careful when you use a punch to remove the "punch pin". It does not require a hard "beating" to remove. Spray a little WD40 on the pin prior to removing it from the mechanical rotating assembly. Also, turn the manual up/down **** to get the "punch pin" in a good position for removal)