Hi
once again I have been screwed over by a garage not knowing what they are doing.
Essentially they had to change the filter and fluid in my gearbox. The have
ended up messing up my headlights. When collecting the car I found the
headlights halfway up and one of the covers jamming the lights halfway.
I have checked out all the usual sites for info on this one but there doesn’t
seem to be a lot out there on the headlight mechanism.
OK
Car is a 1982 928s Euro with H4 lights.
Headlights don’t go up but do go down by the motor.
Manually they raise but as soon as I turn the motor they go down.
With motor running I can not manually raise them.
No light from the headlights at any time but running lights do work.
With motor running I turn on the headlight switch and I can see that the motor
is turning the knob used to manually crank the lights up, this knob is turning
ANTI clockwise very fast.
With motor off I manually crank the lights up but have to turn the knob in a
clockwise direction.
C clips are in place and in good order, all fittings are in good order.
Do you have any solutions ?
Pictures?
Have you come across this before?
If so are there any pictures and instructions out there?
Thanks in advance for any help you can give.
andy
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It sounds like something is jamming the lights. The motor is fairly strong and
will try to raise the lights, and hold them against whatever obstacle it
encounters -- that's why you can't turn the know against the motor. The lights
won't illuminate until they are all the way up. So what could be jamming the
lights? You can see the motor and its linkage to the bar between the lights, so
that area is probably clear. Under the fenders there are bump stops to hold the
lights when they are all the way up -- maybe something is jammed in there
somehow.
If it isn't a physical jam, it is possible that somehow they took apart the
headlight linkage and put it back together wrong, so that the motor doesn't know
when the lights are up or down. You might try disconnecting the lever from the
motor and operating the mechanism by hand (that might help locate a jam also).
If the lights work, I would operate the switch until the motor has returned to
the rest position then reconnect the lever to the lights while they are in the
rest position, and everything should be set back as it should be.
Some 928 owners don't know that the lights are not held down when they are at
rest, or only held down slightly. With the lights "parked" in the down position,
you should be able to raise them one at a time by hand, either by pushing up
from underneath or pulling from the top (if you can get a grip). Trying this
would be another way to check for a jam.
Greg is right -- if the covers are put on wrong, then can jam in the openings.
Hope this helps,
Ray
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Andrew,
Go to:
http://www.nichols.nu/cat18.htm
See if you can find what you need - if not, either reply to my earlier reply to
you, or continue on this thread.
Wally Plumley
928 Specialists
www.928gt.com
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Hi Andrew,
Sounds best like what Ray said: remove the lever and see if the motor does its
thing. I’d expect not. Next is taking the assembly apart and look for loose
wires or bad contacts inside the box at the motor. The position is recognised by
contacts inside the box. Maybe the problem is not related to what the garage did
for your gearbox, but just happened.... or the jamm could have caused a contact
burn... who knows.
regards
Theo
1992 928gts Midnight Blue (2006-)
1988 928s4 Cherry Red (1999-2006)
The Netherlands
http://jenniskens.livedsl.nl
http://928gts.jenniskens.eu
------
Andrew,
The headlamp system is pretty complicated.
If you have the wiring diagrams, look at Page 97-125 and find the "CONCEALING
HEADLIGHT MOTOR". The oddly-shaped symbol on the left side of that box is a
representation of a copper disk that is mounted on the output shaft of the motor
gearbox. It rotates with the output shaft that drives the link arm. The position
of the copper disk determines where the headlamps stop on both ends of travel.
The black lines connected to the input/output wires represent brushes that
contact the copper disk. When the headlamp drives to the down position, the
brush on the brown/red wire hits the inner cutout, telling the relay that the
lights are at a stopping point. When the headlamp drives to the up position, the
brush on the white/black wire hits the cutout 180 degrees away, telling the
relay that the motor is at the other stopping point. The electronics shown in
the headlamp relay at the top of the page then triggers the headlamp contacts to
send power to the headlamps. Other sections of the relay switch the headlamps
from low to high beam, control flashing, etc.
It is possible that the problem with the lights has nothing to do with anything
that the shop did. I don't see why they would have screwed with the lights in
the first place (unless someone in the shop was taking a joyride in your car).
The first thing that I would check would be whether the jamming caused one of
the mechanical connections on the light bar or headlights to move. There are
several adjustments so you can get the lights to the proper positions up and
down. There are also links inside the headlight units that can snap out of
position. Remove both light covers and check for a small ball on the end of a
link that has snapped out if its socket. Check for marks indicating movement on
the light bar. Remove both ends - repeat, BOTH ends of the link between the
motor and the light bar and have a helper turn the ignition and then the lights
on. See if the lights come on. If they do, the motor arm is now at the full up
position. See if the link will fit between the motor and the bar. Be careful -
you don't want the motor or the light bar to move unexpectedly, especially with
your fingers in a pinch point!
If the motor will turn 180 degrees when you turn the lights on, and 180 degrees
when you turn them off, and the lights turn on and off, the wiring, motor and
relay are probably OK. In that case, the problem is probably mechanical
adjustment.
Wally Plumley
928 Specialists
www.928gt.com