Testing headlamp adjustment motors

[mrscalex]

These things have 3 pins and I can't get the motor to move even on a known good one by applying power to any 2 of the pins. I suspect the 3rd pin is to tell the circuit board inside whether the headlamps are on and if the signal isn't high then not to bother.

And bizarrely I can't find the motors on the circuit diagram. See 2001 edition attached.

How do you bench test?

The second part of the query is what is the best position 0, 1 or 2 on the dash switch to change the unit over?

And if everything has got out of whack on both motors where should the screw be manually turned to, eg half way (and on which switch position) to get it all back working together?

Thanks.

 

[Redline]

I would guess that they have 12V an ground on two pins and a variable voltage applied to the third for the levelling with a small controller for the motor.

 

[mrscalex]

I would guess that they have 12V an ground on two pins and a variable voltage applied to the third for the levelling with a small controller for the motor.

Interesting thought. I was thinking they worked off a binary screw in or out, light up or down. But of course they have a 3 setting labelled swith and possibly infinitely variable positions in between.

 

[mrscalex]

This is so wrong I'm transfixed by this video! But it's for self-adjusting systems with an inclination sensor.

 

[the Nefyn cat]

This is so wrong I'm transfixed by this video! But it's for self-adjusting systems with an inclination sensor.

So you go up-hill and the headlamps wind down so you can only see ten foot in front of you? And the opposite when going down again? That's progress, I guess.

 

[NZ00Z3]

Test between all three pins on the unit to see what resistances you get.

Have a look at the 3 position switch and do a resistance test between its pins.

This will give you some idea of how it works.

 

[t-tony]

The beam adjusters only work when the lights are on dipped beam Rob, don't know if you knew this. It could aid your investigations.

Tony.

 

[Bozzy]

Fitted a replacement headlight adjuster that @mrscalex very kindly sorted for me today.
It's the offside head lamp but the light beam is higher than the near side, how do I adjust it ?.

Steve

 

[Redline]

Fitted a replacement headlight adjuster that @mrscalex very kindly sorted for me today.
It's the offside head lamp but the light beam is higher than the near side, how do I adjust it ?.

Steve

Quick search Steve says there should be knurled adjusters in the back of the light, but you have to remove the airbox etc. Apparently there is a work-around - you can use an allen key directly in the gear mechanism from above. Worth a try.

Alternatively, stand in a hole on one side

 

[t-tony]

The coarse adjustment is on the motor rod itself Steve. If the motor is mounted below the centre of the light ( I can't just remember on a Z3) shorten the rod by screwing it into the motor. That will pull the reflector down and aim the light lower. If the motor is mounted above the centre of the light you need to lengthen the rod. Then when you get it somewhere near use the allen bolt or Phillips screw to fine adjust. Did you compare the length of the old adjuster ord and the new one before you fitted the new motor?
A few pictures of the beam adjusters on my Z3 lights.

These were after market lights but are pretty much the same.


Tony.

 

[Bozzy]

The coarse adjustment is on the motor rod itself Steve. If the motor is mounted below the centre of the light ( I can't just remember on a Z3) shorten the rod by screwing it into the motor. That will pull the reflector down and aim the light lower. If the motor is mounted above the centre of the light you need to lengthen the rod. Then when you get it somewhere near use the allen bolt or Phillips screw to fine adjust. Did you compare the length of the old adjuster ord and the new one before you fitted the new motor?
A few pictures of the beam adjusters on my Z3 lights.
View attachment 82641 View attachment 82642 View attachment 82643
These were after market lights but are pretty much the same.


Tony.

Cheers for the info and pics mate
I'll have a go during the weekend.
I did measure them and they weren't far out, it's difficult to tell if the the ball on the end of the adjuster has located correctly in the light.