Service Headlamp leveling motors

[bmnelsc]

Hello all. The headlamp leveling on my 91 S2 is not working consistently so headlamps now cut off on the road 20 feet in front. Ok for around town but not good for highway use. I haven't done the electrical test procedure at the leveling motors but I'm pretty sure the problem is a dirty switch and potentially sticky motors.

I hope to remove the dial on the console and clean it with spray TV tuner cleaner and lubricant (works great on most switches although it doesn't last as long as new grease). I'm also wondering about the stepper motors themselves. Anyone know if these motors are totally sealed or can you get some spray cleaner into them? Also, as special tools are required to remove the motors from the frames, I'm hoping to lubricate them on the car. What are my chances?

Finally - I was reading on a BMW forum (they used the same leveling motors as Porsche in the day) that the headlight leveling motors would cycle through the settings when the headlights were turned on and return to the level according to switch position. Is this supposed to happen with the 944 setup also?

Thanks.

 

[robwright]

The levelling motors only work on the switch. They just move the headlamp frame in and out. You can have a go at opening one up but they are pretty fiddly inside. There is a little circuit board and a servo set up in each motor. Pretty fiddly stuff and I wouldn't fancy your chances. They are also right bugger to seperate from the headlamp frame without breaking it. Your best bet might be some second hand frames or a whole headlight with motor. I got on off of fleabay for a fiver!!! Failing that Alasdair or Elliot. If both have failed in the same position there is also a good chance the potentiometer switch has failed either open or short circuit. Not looked at the circuit myself but I imagine they would default to maximum or minimum if the switch failed open or short circuit.

 

[bmnelsc]

Thanks for the insight on motors - I suspected they would be tricky to remove. I'm sorry to hear they are hard to get apart - I thought they might be well sealed as they are "out in the elements".

As far as failing in a particular location - I believe a bad circuit should fail in full up (position 0) as the electrical test says 0 volts to the motor in position 0 - but - if headlights were in another position when the circuit failed - I'm not sure they would return to zero (wouldn't have power to return the stepper motor to position 0).

Anyone know if the lights are supposed to cycle when you turn them on?

 

[Mike_Pollock]

I think the motors are easy to remove - undo the adjusting screw and the electrical plug, rotote the motor assembly quarter turn and pull - thats how mine came apart anyway!

Edit - just checked - its 120 degrees rotation

 

[bmnelsc]

Thanks for the info - I must confess I haven't looked at these since I changed to North American lenses a year or so ago but IIRC the top left pin is plain while the top right and motor driven pin are cross slotted for adjustment.

Are you saying the adjustment pin can be screwed out of the motor and then the motor turned thru 120 degrees to detach from the frame or must you detach the adjustment pin from the headlight and then turn the motor thru 120 degrees to detach the motor from the frame?

Thanks

 

[Mike_Pollock]

Yes unscrew the adjuster if its not too rusted and rotate 120 degrees and pull.
I can post a pic of the adjuster later if that would help.

 

[Mike_Pollock]

This is a motor, 2 of the 3 lugs are ringed

Dont remove the adjuster screws from the plastic clips as they will break!
(I did as I wanted to replace screws because they were badly rusted)

Hope that helps.