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I was digging into my headlight to determine if I need new gear or just bushings. I think I understand all that from reading other threads.
My issue seems to be with the brushes inside the motor. After my investigation about the gears vs bushings, my motor with not move at all.
I DO have 12v at the brushes when the switch is flipped.
I put the motor is a vise (gently) and applied 12v to the shaft and the motor turned fine.
I cannot seem to get voltage from the brushes to the shaft. When I place the motor back in the housing I AM using fish line to hold back the brushes against the springs, then release them when the motor shaft is in place. I HAVE verified I DO have the small bearing on the end of the motor shaft. Even cycled the battery power off and on.
Am I missing anything??? Is anything computer or power-wise that needs to be done to reset a motor?
I unplugged the other headlight to do some comparison testing and now its dead too. Didn't touch the motor on that one. I believe the motors are fine.... there's something else at play here.
To check the motors with them disconnected, set a multi-meter to check for resistance.. with the probes inserted into the motor connector you should show a low resistance, if you show infinity there is a problem with the motor..
To check the power connector, key off, set the meter to volts and put the probes into the connector, you should get 12v.. If you operate the switch with the probes still in the connector you should get 12v but reverse polarity..
The motor works. Here's a video of me applying 12v on opposing sides of the motor shaft. It works.
ccrazor - Are you saying my mete should read 12v on the car-side of the connector from the green wire to the gray wire with the switch off? How does it get grounded to make a full circuit?
With the Light Sw in Off position you should see +12 Vdc on the Grn wire and 0 Vec on the Gry and Gry/Blk wire till the HL is closed, then you will see +12 Vdc on both wires.
With the Light Sw in Head poistion you should see +12 Vdc on the Gry and Gry/Blk wire with 0 Vdc on the Grn wire till the HL is open, then you will see +12 Vdc on both wires.
From the schematic, with the switch off you get 12v on the dark green from the switch and ground on the light green from the control module.. You get the same on the dark blue and light blue for the other motor.. When you put the switch on you reverse the polarity, 12v light green ground on the dark green..
With the Light Sw in Off position you should see +12 Vdc on the Grn wire and 0 Vec on the Gry and Gry/Blk wire till the HL is closed, then you will see +12 Vdc on both wires.
With the Light Sw in Head poistion you should see +12 Vdc on the Gry and Gry/Blk wire with 0 Vdc on the Grn wire till the HL is open, then you will see +12 Vdc on both wires.
This is basically true if you leave the meter lead on ground, but if you but the lead on a 12v source and the other lead on the other wire you will indicate 12v..
My findings noted in post 10 are from the car-side terminal. I assume thats a straight uninterrupted run back to the module. Perhaps tomorrow I can clamp right on the module to verify.
Motor are fine. Low resist read amd they operate when I manually apply 12v to the lampside of the terminal.
When I first pulled the motor im sure I shorted out the brushes when it came out fuses in the door and fuse block under hood above battery are good. Any others?
From your post 10, it appears that you did not connect the two meter probes to the connector that connects to the motor.. You should get 12v one way with the switch off and reversed with the switch on.. If you are missing any you need a new module..
New headlight module arrived today. Put it in and only 1 motor works. Other motor tested with resistance so its good. I put back together and then it worked! Closed the hood and it didn't work. Jiggle and connector and it worked.
I think I have a short in the wire from the motor to the first connector. Anyone know the gauge size of wire there? Any tips on splicing the wire into the connector and/or motor. Is it best to snip the old wire outside of these items and just heat shrink a new length of wire between them.
Nowhere in this thread did I see a mention of the year of the car.
For future reference: That is important because the headlight control system changed quite a bit from year to year. For example, my car has three relays instead of the headlight control module. The module came later, '87 or '88.
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Headlight Brushes
