Headlamp levelling fault

[Tyred]

Last February at MOT time the headlamp levellers stopped working on my R75 Conn SE. There was no up and down when turning on the side lights and the levelling control did not alter the height. I obtained an alternative light control unit via ebay. That made no difference. In the end I found the earth connections for the headlight units and undid these, cleaned them until sparkling and put them back. Then the levelling motors appeared to work OK. It passed MOT test.
Now the levellers are playing up again and sometimes partially work. Usually leaving the car with the headlights pointing maximum down. I have twice taken the earth connections off the headlight units. Both times the levellers worked for about a day and then stopped again. Today I tried them and they didn't work. I just put a spanner on the light unit earth bolts again and was just able to tighten them the tiniest bit as they are very tight. That was enough to get the leveller motors working again for about 5 minutes. When I tried them again they were not working. I am trying to avoid buying new headlights at £200 each, and having to take the front panel off to take them out. Doing this between freezing weather and constant rain is a problem.

Has anybody had a similar problem and managed to sort it out?
What is strange is that according to the circuit diagram in the Haynes manual, the circuits for the levelling motors are purely via the lighting control unit and don't appear to use the headlight earth. I have tried removing the lighting control unit and used some contact cleaner on a cotton bud to clean the contacts and also sprayed a little into the connector on the loom. I made sure the plug was well seated and the securing yoke in place. The only thing left to try is to solder the earth connection ring connectors on the headlight earths onto the wire in case there is corrosion as they appear to be a crimped connection. It may be that the 'grease' in the motors is stiff because of the cold. I have tried to spray a little WD40 onto the ball joints where the lamps pivot via the bulb opening in the back of the units but this is difficult when they are in place. Has anyone had this problem and managed to sort it? Thanks.

[bendrick]

I'm not one of the experts but when I had a similar problem it was the levelling arms on the suspension had popped out of the ball joint. Put them back and its worked fine ever since.

The plastic arms also sometimes fall into the incorrect position and then don't rise the right way to level the headlights.

[Tyred]

Thanks for your reply. According to the Haynes manual the autodipping only applies to Xenon headlights and I have Halogen. I have a little control wheel on the light control switch module to move the lights down. With the car stood still the levelling adjustment sometimes works. I don't know if its just because the moving part in the headlamp assembly is stiff, or perhaps the lubricant in the motor has dried out or gone sticky or if there is a fault with the control unit or the motors themselves.
Regards

[T-Cut]

Originally Posted by Tyred

Last February at MOT time the headlamp levellers stopped working on my R75 Conn SE. There was no up and down when turning on the side lights

Turning on the sidelights doesn't activate the self test for the headlamps height adjuster. Turning on the headlights with the ignition on does that. However, I found the self test only operates every few sessions. The non-HID headlights (those which use filament bulbs/ 'halogen') aren't self leveling, but are manually adjustable using the thumbwheel. The self test checks that the motorised adjustment is operating by driving the control motors across their range. They should return the lamps to the position they were last set manually. If you adjust the beams to their lowest setting, they will stay there until you re-adjust them. The self test will still raise/lower the reflectors and then return them to the set position.

Failure of the self test or the manual adjustment may be electrical or mechanical. Yours seems to be electrical. The most common cause of problems with headlamp electrics is chafing of the harness on the right side body seam (under the wheel arch).



Take off the front bumper and check the harness. It's near the screen wash bottle.

The mechanical cause of a faulty self test or manual adjustment is stiffness in the linkage between the stepper motor and the reflector. The reflector has a three point mounting which allows it to be pivoted up/down and left/right. Here's a photo of the reflector showning the three pivots. The stepper motor pushes/pulls on the lower point.



The only way to check and fix mechanical issues is to open up the lamps to access the mechanism. It's pretty straight forward, but requires you to heat the lamp in the oven to soften the sealing mastic. This allows separation of the front lens and case. It can also be messy, but lots of members have done it. If you have to go down that route there's lots of info available.

TC

[Tyred]

Thanks for the reply T Cut.
Yesterday afternoon I managed to put some solder on the earth connectors on the offside headlamp and that seems to have done the trick. Its been raining most of the day and likely tomorrow so I won't be able to have a go at the nearside ones until friday. The improved earth on the offside appears good enough to make both motors work OK. I want to solder the nearside connectors as well just in case. Looking at the wiring diagram in the Haynes manual it suggests that the motors have two wires each and that these connect directly to the light control unit. There is no connection shown between the motors and the headlamp earth. In the case of my car the headlamp earth connection is certainly being used. Perhaps the MK1 and MK2 headlamps are wired slighty differently. I did try another light control unit but I am not sure whether that was from a MK1 or MK2, they look the same to me. Changing the unit didn't clear the fault.

With my car ( 2004 Conn SE mk2 CDTi) when I turn on the sidelights the headlights go through the down/up sequence. When I then turn the key to ignition position and turn on the headlights, I can move them down and up using the thumbwheel. I am not sure if that is exactly right, but you do say yours are a bit intermittent?



On my car I have a piece of rubber protection over the panel edges you show.

I have managed to put a bit of WD40 on the light pivots you show. I can get the red tube on the WD40 can into a bigger plactic tube and then point it at the bearing points by taking off the little panel under the wheel arch and removing the rubber cover from behind the headlight. I can see into the back of the headlight unit using an LED torch.

I am hoping that I have found the problem with the earth connectors and that was the reason for the motors working for a while after tightening the earth bolt, due to the wires being moved improving a poor connection in the connectors. The levellers are still working today when I checked them.
Regards.

[T-Cut]

Originally Posted by Tyred

Perhaps the MK1 and MK2 headlamps are wired slighty differently. I did try another light control unit but I am not sure whether that was from a MK1 or MK2, they look the same to me. Changing the unit didn't clear the fault.

I'm not aware of any differences in the wiring. The light switch unit is the same in Mk1 and Mk2 models. For any queries on headlamp wiring, contact Rick-Sta who works on headlamp stuff.

With my car (2004 Conn SE mk2 CDTi) when I turn on the sidelights the headlights go through the down/up sequence.

That seems unusual to me, but maybe I haven't noticed (2004 1.8T). I've only observed it when the headlamps are switched on. Maybe others will comment on that?

When I then turn the key to ignition position and turn on the headlights, I can move them down and up using the thumbwheel. I am not sure if that is exactly right, but you do say yours are a bit intermittent?

Your thumbweel control is now correct. What I meant by 'intermittant' is the automatic up/down self test. I don't think mine does this every time. More like every three or four switch-ons.

On my car I have a piece of rubber protection over the panel edges you show.

Good, someone's already fixed the chafing problem.

I have managed to put a bit of WD40 on the light pivots you show.

I'd avoid spraying anything oily into the lamp case. The pivots don't need any lube and you might fog up the reflector unit. Problems inside are typically due to detachment of the pivot points and stiffness in the stepper motor's push arm.

It seems like you've fixed your lamps, though I'd ask for more clarification on the side lights and the self test.

Maybe get a Handbook? Here's the early edition, but is 99% relevant to the Mk2: http://storm.oldcarmanualproject.com...nersmanual.pdf

TC

[Tyred]

Thanks T-Cut.
I have a drivers manual but they don't mention the test seqence of the levelling system. I found out about them going through the test sequence when a friend was standing near the car when I turned the sidelight switch and they commented on the lights going up and down. I got them to turn the sidelights on for me so I could see what happens. With the ignition off, when you turn the sidelights on the dipped beam projector lenses noticably tilt down then up. The dipped beams are not illuminated. You can hear the noise of the motors. With the lights turned fully off, if you turn the ignition on and quickly move the light switch to headlights you can see the light pattern in front of you going down and up, this time because the lights are still going through the same test sequence but the headlights are on so there is a beam that you can see moving.
I managed to solder the other earth connections, this time on the nearside.

The levelling is working at the moment and will hopefully continue to do so for MOT test in a couple of weeks time. Hopefully the levellers won't decide to stick in the down position again which is what happened last time I was out. Thanks for your help. Regards

[T-Cut]

Interesting, I'll check that out (if I remember that is).


TC