The following is an article published in the first quarter 1995 "Fiero Owner" magazine that is distributed by FOCOA. It describes a no cost procedure to repair headlights actuators that continue to turn after the headlights are completely down.
I am sending this info out to anyone who has experienced headlight troubles, (mainly 84-87's) where it continues to run after they have turned off. I have had this problem on two of my 3 Fieros, and many of my friends also have experienced this problem. When the problem occurs, you will see the headlights drop when you turn them off as usual, but if you listen, and annoying grinding noise can be heard. The sound seems to be coming from the one or both motors. The noise wont quit until you unplug the motor or you turn the lights back on.
What happens is the grease gets old inside the motor, and turns almost rock hard! When this happens, there is a lot of extra tension on the main drive gear inside which is plastic, due to a high resistance from the hard grease. Eventually, something is going to give, and more than likely it will result in 3-5 teeth breaking off, or being chewed away.
Owners who want to spend hundreds of dollars on a new one, or $30-$50 for a used one could do so, but the problem can be fixed as good as new, and it wont cost you a dime.
THE FIX: The first thing you need to do is raise the headlights and unplug the blue wire on the defective motor. This will give you room to remove the top and bottom 10mm nuts holding the headlight assembly in place. After removing the four nuts, unplug the relay wires, and light wires. Remove the assembly. Next remove the small clip from the linkage that attaches to the motor. Then remove the three bolts holding the motor in place. With the motor removed, drill out the rivets holding the motor with a vise. You can now split the case of the motor with a standard screwdriver. You will find notches in the middle of the case where your screwdriver should go. This will prevent you from jamming and prying into the middle of the case and damaging the surface. Now, with the case split, DO NOT ROTATE THE MOTOR IN ANY WAY! What you need to do now is mark the position of the main drive gear. This is the plastic gear with the shift sticking out the side of the case. Make marks on the gear, and on the case. When putting the motor back together it is very important to know the exact position of the gear after you split the case. Now, remove the two gears inside and clean all of the old grease. Soaking them in a degreaser will help loosen the grease, so it's easier to remove from the inside of the teeth. Now you can use fresh wheel bearing grease in all of the gears inside. Be sure not to get any on the motor brushes. After greasing the gears, find you mark on the case. Re-install the damaged gear 180 degrees from the original position, or the exact opposite position that you found the gear before you removed it. Reassemble the case. It may be necessary to use silicone sealant if the old seal was damaged after you split the case. Now with the motor back together you can either re-rivet or use self taping screws to secure the case back together.
This method of repair will work because during operation the motor only uses half of the main drive gears. While the assembly is out of the car it's a good idea to grease all of the linkage. All you have to do is remove the small clips and linkage, then use fresh grease on and under the plastic bushings. Re-assemble and re-install the headlight assembly back into your Fiero. You might want to clean and re-grease the other motor, to prevent the motor from going bad. You should notice the motors will work faster and quieter. Since there is less strain on the gears, linkages, and motors the whole open and close operation should happen more smoothly.
Thanks K. Norwick
Bill sez: This is a very good suggestion and fix but if you have bad limit switches the problem may continue.