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-   -   headlight motor repair (https://rennlist.com/forums/928-forum/35920-headlight-motor-repair.html)

John V 08-30-2001 02:21 PM

headlight motor repair
 
Hello to all!
just found this forum yesterday and was very impressed with the knowledge base. great forum!
I'm rebuilding 1981 928 (affectionatly called "moneypit"). Love the car but has lots of gremlins. Latest quirk is a headlight motor that raises intermittently. When working, lights lift then turn on. When not working, lights turn on as soon as dash switch is activated, but the lights fail to raise. They can be manually raised and will go down when you turn off the lights, but won't re-raise automatically. I've looked at the schematics and it appears that there is some sort of switch(s) inside the motor (I presume to control the start/stop point of motor rotation up and down??). Anyone have any insight or know if this is serviceable?

Thanks in advance

Randy V 08-30-2001 04:05 PM

Hello John - welcome.

First thing to try would be to replace the relays and fuses associated with the headlight functions. You can also try troubleshooting by swapping the headlight relay(s) with another of the same type on your fuse panel used for another system.

Click on the enclosed link to go to 928 Specialist's fuse/relay charts:

928 Specialists Fuse/Relay Charts

Let us know how it's going.

John V 08-30-2001 05:01 PM

Randy,

unfortunatly, the headlight relay is unique and not compatible with any others in the box. I could get another but in my mind, the problem appears to be in the motor assembly??
I would think there has to be a sensing device to cut power to the motor(or release the relay) when the lights are up or down... or else the motor would just keep spinning. From the schematics I have of the motor, it appears that there is an internal mechanism that is driven by a disc with a knotch cut in it. My schamatic for the motor and relay isn't real clear and I cant seem to grasp the entire circuit.
My interpretation of the sequence (I could be way off) ... relay coil is energized by dash switch. Headlight motor is energized through a switch (SPDT) in the motor that allows the motor to turn though a closed contact, lights raise until the switch is tripped, switch trip shuts off motor (opens contact) and (closes other side of switch) powers another relay coil which lights either high or low beam depending on selector switch. If I'm correct, that would cause the lights to come on but would never energize the motor because it would think the lights are already up.

Does this sound possible or am I out in left field?

Jamey 08-31-2001 02:13 AM

John, failure of the headlights to raise or lower properly is often caused by a misalignment of the motor and the 2 bars that rotate the headlight bar. This can be adjusted by loosening the motor and repositioning it so the 2 bars are not dead straight with each other when the lights are up or down. In other words...the 2 bars that are linked together have to be at different angles to have the ability to rotate the headlight bar. Watch your fingers while working on this because the 2 bars act like scissors as they turn. Be sure to replace the small circlips so the bars won't come loose and ram into your radiator when turning on your headlights someday. Goodluck.
www.geocities.com/jamey928/index.html

John V 08-31-2001 09:11 AM

Jamey,

I have actually gone as far as disconnecting the motor from the arm all together (thinking the motor might be tired and not having the umpff (technical term :D )to raise but enough to lower). No differnece... motor don't turn. Then at times with everything hooked up, lights work fine.
One other reason I think its internal, is if the motor doesn't work, I can wiggle the wires, reset the relay and it doesn't help but, if I tap the motot with a mallet, voila... they work. Seems like somethings getting stuck inside.

928Collector 10-18-2023 11:39 PM

Head lights pop up then down when i turn the manual screw
 
Can anyone help with headllight motor fixes?
Q1: My head light does not go up when i turn the head light button clockwise(not counter clockwise). I tested this on my other 928 and it seems to turn on and pop up the headlights the button on the instrument cluster is turned counterclockwise?.
Q2: when i turn the manual screw on top of the head light motor (see blue arrow on image) counter clockwise the head lights pop up then pop back down. i cant get the head lights to stay up with this manual screw. Also the lights do not turn on when they pop up and pop back down.
Its not the relay. Its not the fuse.
Maybe its the switch.
the headlight motor arms are secured with circlips and do not hit the radiator in anyway.
both headlights go up then down so no issues there.
The headlights were working 2 months ago when i last drove the car so this is very strange.
any help/advice much appreciated.

https://cimg2.ibsrv.net/gimg/rennlis...3fae2a3014.png

Mrmerlin 10-19-2023 10:10 AM

what year is your car?

928Collector 10-19-2023 11:35 PM

1980. Sorry i should have included that.

928Collector 10-19-2023 11:43 PM

Head light motor removal on a 1980 Porsche 928
 
What is the easiest way to remove the head light motor? I want to open it up and clean it but i'm having trouble seeing which screws hold the motor onto the arms. Do i just loosen the blue nut? or do i have to loosen the three red nuts to remove the motor?
https://cimg7.ibsrv.net/gimg/rennlis...701fdcefab.png

Mrmerlin 10-20-2023 10:10 AM

mark the arm to the shaft,
then remove the blue nut,
then remove the arm from the shaft,
then remove the 3 anchor bolts,
then pull the motor free

928Collector 10-20-2023 12:43 PM

OMG - Marking. Yes. you probably just saved me a lot of time and trouble. Thank you. I get emotional about these sorts of oversites on my Shark...Thank you...lol...

jpitman2 10-24-2023 04:24 AM

There are copper traces inside , wiped by arms telling the motor where the external arm is currently. Dried grease or corrosion is not our friend. One of the common charts out there shows which wires at the 4 way connector (flat, in line)go where, BUT it didnt match my car. Make a note, take a picture before you separate that connector.
jp 83 Euro S AT 57k

928Collector 11-05-2023 01:27 PM

Head light motor marking / before removal?
 
Thanks. Can you direct me what to "mark" before removal?
https://cimg6.ibsrv.net/gimg/rennlis...d9a4b24d73.png


928Collector 11-18-2023 07:40 PM

Headlight motor removal on a 1980 928
 
How do i remove the actual head light motor after i've taken off the center nut and the three mounting nuts? the screw that holds the motor to the bracket is too long to just stick a screw driver to lift the mounting bracket from the headlight motor. and even then headlight motor because of its shape gets stuck. i've tried wedging it out up, forward, even down.
https://cimg9.ibsrv.net/gimg/rennlis...61a7ab5431.png
i've removed the three (blue arrow) nuts. and the center (red arrow) nut. But the head light motor itself cannot be wedged out.
https://cimg2.ibsrv.net/gimg/rennlis...1abb63ac09.png
Do i need to remove these circlips? If so, how do i do so? do i need a special circlip removal tool? A screw driver or a visegrip doesnt tap or knock or pull these circlips out.
https://cimg8.ibsrv.net/gimg/rennlis...127f39f179.png
It seems this center screw is too long to wedge a screw driver in and separate the holding bracket from it. Also the motor is too snug a fit against the fender to create space for the screw/bracket to be separated. Do i need to remove the two circlips? If so how do i do so - is there a special circlip removal tool?
https://cimg0.ibsrv.net/gimg/rennlis...bc8c15f3ac.png
these are the two circlips. they are not the usual circular circlips. and i have not been able to find this "E circlip" removal tool

928Collector 01-25-2024 02:59 PM

Gentlemen:
Given the support/instruction/pictures above, just to bring this full circle its:
-disconnect battery
-put the lights in full resting position and take pictures of the location of the arms.
-remove the circlips. they pop off with a screw driver. when you put them back on be sure the two prongs are on bottom and the full bent bar/tab is on top. you'll be able to snap/press the tab into place.
-with the circlips removed, pull off the 3 nuts and the center nut.
-its not necessary but if you'd like remove the center grill to the hood - easy allen head nuts
-with the center nut removed, use a pry bar to pop off the arm as the arm is engrained into notches on the motor. this center nut arm determines the up/down position of the motor and the headlights.
-screw off the two side bolts and pull off the top motor - note the top is magnetized so you may have to use some force. deoitx clean the insides thoroughly
-remove the 4 screws on the bottom motor. deoixt/clean the motor parts thoroughly.
-put the top motor and bottom motors back together
-by hand reinstall motor into the engine bay - tighten the three screws but only hand tighten the center nut screw
-reinstall two circlips (two leg prongs down/continuous tab up) on the center arm
-reconnect battery, insert key in ignition and on the instrument cluster turn light switch to the right to raise headlights. Perform any required adjusts by turning the small screw on top of the headlight motor motor as well as by loosening the center nut and adjusting/removing the center arm. this make take some back and forth but the center arm that is released by the center nut is what sets the motor/light position.
This is an easy/mid level job so if you get stuck see above/prior and/or ask the forum as a couple of thoughts or pictures would easily save a lot of frustration. .


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