Headlight Gears Replaced - Now Headlight motor is randomly engaging in off position. (Page 1/1)
lurtz JUN 16, 08:52 AM
Hello Everyone!

1984 4spd. No mods. 125k miles. zero rust.

I brought the car out of winter storage a few weeks ago, and after a couple of uses, the driver's side headlight motor started grinding the 37-year-old gears to dust. No problem, as I had a spare rebuild kit from Rodney after I bought two kits a couple of years ago when the passenger side succumbed to age. I replaced the gears and rubber "bushings" and re-greased and put everything back together. Everything seemed fine until I noticed that the headlight motor is "engaging" every 20 or so seconds for a moment and then stops. Like I can hear the relay click on, and the motor tightens (no actual movement of the headlight assembly) and release. It is doing this enough to the point it drained my new battery in three days of non-use.

Another symptom is sometimes when I engage the headlights, my passenger side goes up instantly, but the driver side hesitates and, with no repeatable frequency, decides to come up after the first. To clarify, once the motor engages, the speed of the headlight bucket moving through its motions is just as fast; there is just a random delay in starting the movement.

Does anyone have any idea what is causing this to happen? Any suggestions as to how to fix this?

Thank you.

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1984 Base Coupe Red Stock MY8

2002 Grand Prix GTP 40th Anniv. Stock (Now Donor Material)

fierofool JUN 16, 09:38 AM
Remove the motor and look underneath the knob to see if the rubber weather seal is visible. A common mistake is to leave this seal outside the case. When the motor torques and pulls the motor assembly downward, the rubber seal will not allow full disengagement of the limiter switch point set. The thermal switch takes over and the motor will re-engage and 'twitch'. There are two cavities in the top of the case halves. The lower one gets the brass D bushing and the top cavity houses the rubber D weather seal.

The motors are not physically or electrically connected. Though there is one power source, that source is separated at the isolation relay on the driver's side fender wall. The motors will operate at different speeds depending upon several factors. It may be that there's a little degradation in that side of the isolation relay and it reacts a little slower at energizing the motor relay. And again, it might be due to the rubber weather seal.
lurtz JUN 16, 09:54 AM
Thank you! I will take a look at this and adjust if necessary. I can see the logic on how this would cause the issue.
fierofool JUN 16, 01:24 PM
Visit www.gafiero.org and go to the message board. Look for Club News then 2021 Newsletters, April edition. On page 16, you'll see an example. The April 2021 covers headlights extensively.
lurtz JUN 16, 11:21 PM
Thank you so much!!! You nailed the issue right on the head. I had not aligned the rubber seal appropriately. Everything is acting as it should now, including the raise and lowering in sync with the passenger side.


The write up is also well done.

Have a great day.
fierofool JUN 17, 09:53 AM
lurtz JUN 17, 01:54 PM
+1 Positive Rating for you, sir! I can't believe you were able to diagnose the problem so quickly.
fierofool JUN 17, 08:11 PM
I rebuilt Generation motors for more than 15 years.