1984 Headlight question... (Page 1/1)
David Riedle SEP 09, 07:09 PM
I have a 14,000 mile Indy that is having an odd headlight issue. I have rebuilt both motors due to the disintegration of the gear and bumpers in my passenger side motor.

I replaced the gears and bumpers in both motors with aluminum gears and delrin bumpers, and the motors work well.

The issue that I am having is that my passenger side headlight will sometimes not go up. Turning the manual knob 10 degrees always makes the headlight go up. What is strange is that the headlight won't go up when the car is in the garage. When I drive the car on the road for a mile, it usually will work, and if it won't go up when I am driving, it will usually go up if I try it immediately. The grounds seem tight, and when I replaced the gears, the motors were like new inside, with the exception of the gears and bumpers.

Could I have a relay issue?
Dennis LaGrua SEP 10, 05:47 PM
If the problem is confined to one motor then its likely the headlight relay or an internal motor problem. First check the relay. If OK, how are the brushes on the motor? Do they look solid or well worn? If they are well worn they may not always make a good connection to the motor armature.

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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

FIREBOX SEP 21, 02:10 PM
motor contact issue likely since turning motor shaft "slightly" starts it. Try just tapping the manual knob to get it running.
fierofool SEP 22, 11:30 AM
That would indicate that the limiter switch point set failed to open at the end of travel. The bump opens them, allowing the opposite set of points to close and power the motor in the opposite direction of last travel. Power is still being applied until the point set is opened. No power is applied to the opposite until the light switch is activated to complete the circuit for that direction of travel.

In the dash switch, there are two circuits. One closes when the switch is turned on. That powers one side of the motor relay to raise the headlight. Power continues to be applied to that circuit, but the point set for UP should open at the end of travel, hence the circuit is now OPEN.

At this point, the point set for the DOWN movement is closed, but there is no power applied to that circuit until the dash switch is turned OFF. That completes the circuit and at the same time disconnects power to the UP circuit. At the end of travel in the DOWN movement, that pointset opens. Anywhere between fully open and fully closed, both point sets in the limiter switch are closed. There's just one side that is energized, dependin upon the position of the dash switch.
theogre SEP 22, 05:41 PM
metal gear is likely ok...
Delrin bumper will cause problems.

If are pushing Delrin and anything hard as bumpers in Gen1 motors... will break something that weaker same as covered in this thread for Gen2 HL motors:
https://www.fiero.nl/forum/Forum2/HTML/128600.html

GM made the bumper "soft" so motor shaft can safely hit End of Travel or jams and softer then everything else.
Plus keeping a load in the bumpers @ EoT make limit switches to stay off even if motor shaft tries to back off for vibration or sit for months.

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Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

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Dennis LaGrua SEP 22, 06:35 PM

quote
Originally posted by theogre:

metal gear is likely ok...
Delrin bumper will cause problems.

If are pushing Delrin and anything hard as bumpers in Gen1 motors... will break something that weaker same as covered in this thread for Gen2 HL motors:
https://www.fiero.nl/forum/Forum2/HTML/128600.html

GM made the bumper "soft" so motor shaft can safely hit End of Travel or jams and softer then everything else.
Plus keeping a load in the bumpers @ EoT make limit switches to stay off even if motor shaft tries to back off for vibration or sit for months.



Must agree here. The impact softening and load storing effect of the internal rubber gear inserts is critical. It provides the shock absorbing function at the end of travel. This keeps the gear from being stripped out. If you use the Fiero Store repair kit for the Gen 1 motors it contains soft rubber inserts. The Delrins are usually provided in the Gen 2 repair kits. They are hard and do not cushion. While this repair can work for a while, I do not like them. I just replace the entire motors with new ones. They are $50 ea on eBay.

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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

theogre SEP 22, 06:41 PM

quote
Originally posted by Dennis LaGrua:
I just replace the entire motors with new ones. They are $50 ea on eBay.

Seen and Bought New Gen2 motors. But Not Gen1 motors...
David Riedle SEP 22, 07:10 PM
I wondered about the delrin "bumpers". I wondered if there was not enough give to the bumpers based on the tiny amount I had to move the knob. I think I should replace the relay, since this is the motor that did not shut off. Are just the bumpers available?
fierofool SEP 22, 09:33 PM
Swap relays between motors and see if the problem goes with the relay.

I think Rodney sells a viton rubber bumpstop set.
buddycraigg SEP 25, 08:32 PM
The problem is in the motor most likely.

I guess the contact in the isolation relay could be bad for that side. I would really suspect the motor though.
You can try this without taking the motor completely apart.
Take out the limit switch.
then stick a scotchbrite pad in there where the commutator is and turn the motor by hand a few times.
Then some fine sandpaper to clean up the contacts.
Put it back together and see if it is better.

[This message has been edited by buddycraigg (edited 09-26-2021).]