On my 96 Conv. the right headlight electric motor keeps running after the light has completed cycling. This causes the shaft on the new plastic gear (and bushings) to become slippery and the light stops cycling. The electric motor stops on it's own after about 10-15 seconds. Is there a controller somewhere which tells the electric motor how long to run??

 

We need more info.

Are you saying you recently replaced your old gear and bushings with new ones and are still hearing your motor run 10 to 15 seconds after the door closes?

If that's the case, it sounds like your headlamp motor assembly might have a stripped gear. The nylon (hard plastic) gear inside the assembly occasionally breaks the last few teeth it "bottoms out" against.

Here's how it works:

1) the motor is activated and starts turning the nylon gear.

2) the headlamp assembly rises/falls due to the turning output shaft linked to the underside "arm" of the headlamp assembly.

3) the assembly hits steel "stop points"

4) a resistor senses the increased load on the gear/motor (since the motor is trying to run and can't move) and cuts the signal/power.

The "turn till you stall" approach was used on most GM headlight assemblies, including the fragile C4 assembly which was more notorious for breaking than oh, say, Firebirds, Fieros, and Buick Reattas.

The weight of the assembly hitting the stop point (while being pushed by the motor) eventually breaks off the last few teeth of the nylon gear.

After the teeth are broken/stripped, the motor runs full out in spot with no load. The signal never cuts out because of this, and you just have to wait for the signal to "time out".

So what are your repair options?

Fix #1: replace the whole lighting assembly. The motor, gear, housing are sold as a complete unit so you gotta buy the whole $100+ unit. OUCH.

What happens when you're sick of replacing a perfectly good motor due to the nylon gear breaking?

Fix #2: Brass gear. But the good news is, the bushings usually fail long before the main gear.

Eventually Mid America Motorworks (www.MADvet.com) came out with a bronze replacement gear (Part# 17531) to solve the gear problem.

PS, using plastic-lens sealed-beams instead of the heavier glass versions will help prevent damage to the gear teeth.

Also, try not to turn off you lights until the car has stopped moving. Coinciding regular vehicle bumps with the "stop point impact" can increase your chances of stripping the teeth.

 

this sounds like your gears are beginning to get stripped ... The headlight motor is stopped once it finishes the cycle (theres a rubber stopper on the hood that stops it when the full cycle is complete)... when I replaced mine I saw that my motor kept going and when i placed in the car it stopped once it hit the hood. you can always open your motor and look at your gears... my $.02

 

The left light lifts about 4 inches and stops, is that the gear? but motor stops ok.

 

That sounds like a bushing issue. They are much more failure prone than the main gears. You can order them online from Mid America Motorworks (MAM) or Eckler's Corvette Parts, then use these instructions to install..

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

 

Good link on the headlight bushings, seems like a good saturday project, sure makes sense to do both at the same time. Thanks

 

That's what I did. Fixed mine both of mine on a summer Saturday. You can also find nylon spacers at Home Depot of Lowe's that will work. I bought Home Depot bushings (item no. 859609) at a price of .69 cents for a pack of three. You will need six to fix both lights.