Headlight levelling motor testing

[WarthogARJ]

Hi,
My headlight levelling switch doesn't seem to adjust my headlights.

Initially I thought was the motors since when I pulled them they didn't do anything when I powered them.
But maybe I did that wrong, maybe they ARE in fact OK.

Any idea how I can test a motor on its own?
I have the Haynes generic wiring diagram, but that doesn't really tell me.
And in fact it's not the same as what is actually in the Ford Transit.

The motors have 3 wire inputs: I can use a RC plug to test them independently.
The wire colours (from the light box module) are:
Black (ground) (on LEFT)
Blue/Red (middle)
Orange/Green (on RIGHT)

This is oriented by holding motor in hand looking at 3-wire input, and rod pointed DOWN.

I know black is ground from connectivity to other parts.
If I connect Blue/Red to +12V then......nothing.
BUT if I then touch Orange/Green (by fingers) the motor starts to turn....aha!!

I think Orange/Green is the vaguely referred to in the depths of More. Google the "sense" wire....which is what?
In terms of volts and amps.

Sir Haynes OBE claims that the Level Switch is a rheostat that would then adjust the volts: from +12V to less.
But he only has TWO wires per motor module (Module 21 and 22 on his "Typical Headlight Levelling" diagram).

In fact, Mr. Ford uses THREE.

The control rheostat in the instrument panel SEEMS to be OK: as I turn it, it changes resistance.
And physically seems connected correctly.

The wiring seems OK too.

I can manually turn the adjustors: not easy, but am not sure what they are usually like.
I have cleaned them, and lubricated with silicone grease.

I have also spliced in extra wires to the light modules where I can monitor voltages if I need to.

If needed I can heat the light module and pull apart: have seen on Youtube.
So I can inspect the adjusting gears.
Suspect I could swap out a worn one from the unused foglight ones: they seem to be the same type.
And I have the butyl rubber sealing strip to seal up again.

But I'd like to test the motors before I start pulling the units apart.

I bought a new one (which I cannot get to work by the finger on sense wire...??).
And a used one where I CAN.
And my own that I CAN get to run with the sense/finger thing.

Attached is the Haynes generic wiring diagram:

The related question is how do you set things up after reinstalling a motor you've fiddled with?
You can manually adjust the headlights up/down.
Can set the Headlight Level switch at zero to 5.
Can get the motors turned all way IN or OUT.

And then there's TWO of them: I guess if you manually align the light modules so both are aimed the same, then the motors work the same?
Or at least close enough.

My guess for re-installation:
Headlight Level switch to zero
Headlights manually turned to point UP as far as they will go (by turning plastic knobs).
Motors wound IN as far as will go (this pulls the lever IN at the motor end, and pushes the headlight to point UP

I THINK that's the ZERO position.
So you adjust the Levelling Switch to point them DOWN.

Seem logical?

The motors seem to be very geared down high torque/slow turning worm gears.
Must be some sort of internal switches to know when they are at max IN or OUT.
And must be some sort of way they know to turn one way or the other (to turn the rod IN or OUT).
I think that's the mysterious "sense" wire.

I have four motors now: so I will dissect one if nobody knows how it works.
Seems strange that Mr. Google says nothing about this little beastie??

Thanks for help
Alan

[WarthogARJ]

This is very strange.
I've been searching Mr. Google and I nothing on how these headlight levelling motors actually work.

You'd think with millions of Fords using them that SOMEONE would have taken one apart by now and written about it.
Like I know they fail.

Well, I did, and I'll write it up.
Is surprisingly complex inside, but I think I've got it figured out.

[Jim Archer]

Check the fuse.

How long were you waiting for a response? My Mk7 ones take a fair few seconds to start moving.

Jim

[v8dave]

The motor in the headlamp is a servo.

The control on the light switch acts as a variable voltage source.
The headlamp motor adjusts it's position based on the voltage from the switch.

The motor only has power to move if the side light is powered.
It is earthed separately in the headlamp connector but shares the same earth point on the body with the lights.

[daraioj]

Hi,
My headlight levelling switch doesn't seem to adjust my headlights.

Initially I thought was the motors since when I pulled them they didn't do anything when I powered them.
But maybe I did that wrong, maybe they ARE in fact OK.

Any idea how I can test a motor on its own?
I have the Haynes generic wiring diagram, but that doesn't really tell me.
And in fact it's not the same as what is actually in the Ford Transit.

The motors have 3 wire inputs: I can use a RC plug to test them independently.
The wire colours (from the light box module) are:
Black (ground) (on LEFT)
Blue/Red (middle)
Orange/Green (on RIGHT)

This is oriented by holding motor in hand looking at 3-wire input, and rod pointed DOWN.

I know black is ground from connectivity to other parts.
If I connect Blue/Red to +12V then......nothing.
BUT if I then touch Orange/Green (by fingers) the motor starts to turn....aha!!

I think Orange/Green is the vaguely referred to in the depths of More. Google the "sense" wire....which is what?
In terms of volts and amps.

Sir Haynes OBE claims that the Level Switch is a rheostat that would then adjust the volts: from +12V to less.
But he only has TWO wires per motor module (Module 21 and 22 on his "Typical Headlight Levelling" diagram).

In fact, Mr. Ford uses THREE.

The control rheostat in the instrument panel SEEMS to be OK: as I turn it, it changes resistance.
And physically seems connected correctly.

The wiring seems OK too.

I can manually turn the adjustors: not easy, but am not sure what they are usually like.
I have cleaned them, and lubricated with silicone grease.

I have also spliced in extra wires to the light modules where I can monitor voltages if I need to.

If needed I can heat the light module and pull apart: have seen on Youtube.
So I can inspect the adjusting gears.
Suspect I could swap out a worn one from the unused foglight ones: they seem to be the same type.
And I have the butyl rubber sealing strip to seal up again.

But I'd like to test the motors before I start pulling the units apart.

I bought a new one (which I cannot get to work by the finger on sense wire...??).
And a used one where I CAN.
And my own that I CAN get to run with the sense/finger thing.

Attached is the Haynes generic wiring diagram:

The related question is how do you set things up after reinstalling a motor you've fiddled with?
You can manually adjust the headlights up/down.
Can set the Headlight Level switch at zero to 5.
Can get the motors turned all way IN or OUT.

And then there's TWO of them: I guess if you manually align the light modules so both are aimed the same, then the motors work the same?
Or at least close enough.

My guess for re-installation:
Headlight Level switch to zero
Headlights manually turned to point UP as far as they will go (by turning plastic knobs).
Motors wound IN as far as will go (this pulls the lever IN at the motor end, and pushes the headlight to point UP

I THINK that's the ZERO position.
So you adjust the Levelling Switch to point them DOWN.

Seem logical?

The motors seem to be very geared down high torque/slow turning worm gears.
Must be some sort of internal switches to know when they are at max IN or OUT.
And must be some sort of way they know to turn one way or the other (to turn the rod IN or OUT).
I think that's the mysterious "sense" wire.

I have four motors now: so I will dissect one if nobody knows how it works.
Seems strange that Mr. Google says nothing about this little beastie??

Thanks for help
Alan

(Pic from http://www.fordfiestast.co.uk/showflat. ... ber=342024)

One of mine was dead when I bought the van. Get the servo out and take it apart. You'll see it's a very simple mechanism. But the electric motor is not soldered to the board. It's got a couple of pins that go inside some contact holes. They were all dirty on mine. Cleaned them, put it back together and it's been working fine since.

It will self adjust. It "knows" where it's at.

You might need to adjust the actual headlight (with an hex key) so they're both at the same night.

[Jim Archer]

There is a potentiometer on the drive screw, the signal voltage from which is compared by the wee board to the reference voltage of the dash height adjuster switch - or on Xenon/HID equiped vehicles, the rear ride height sensor.

Jim