blimey thats a mouthful.

SWMBO's Hatch has failed the MOT on the headlight levelling switch not working of all things ??? is that legal ?

Surely as long as it can be manually adjusted and is within the correct adjustment it should pass?

Anyway I digress.

How does this system work and how should I go about troubleshooting it and fixing the problem?

Looks like there should be a motor in each of the headlights which is controlled by the rotary switch on the dash . I have no idea if the is a seperate fuse , whether it has a circuit board somewhere or even where the motors are as I cannot see much without removing the headlights.

Hope someone can cast some light on the subject lol

I think it's a requirement now that cars must have a headlight levelling system. Some cars have automatic systems, but most just have the little dial that you turn. It's to make sure you don't blind other drivers when you have a full load in the back. So yes, it's probably legal for them to fail the car for that.

new rules this year state it must work or its a fail im afraid it may be a faulty switch or the motors are gone start looking at the fuses under the bonnet

ok I've done a bit of squinting at the electrical schematics in the manual and I think I have finally cracked it.

A live feed goes to one side of the leveling switch (which is a rotary rheostat)

The other side of the rheostat goes to earth

The centre tap of the rheostat feeds the variable power supply to both the headlamp levelling motors on a Blue/Red wire

I need to remove the 2xwire connector to both the headlamp motors and switch the ignition on and test I have a voltage .

if I have voltage then I need to check the earth to the motors is good.

If both the live feed and the earths to the motors are ok then the motor/s might need replacing.

If the earth is good but there is no power from the switch I need to check the 12v supply to the switch (when I can find where it comes from grrrrrrr)

It looks like it shares the feed from the headlamp washer fuse . (Diagram 10 Haynes manual)

If the motors and earths and rheostat supply is ok I'll need to check/replace the levelling rheostat or replace any defective wiring if there is a break somewhere.

Now if it will just stop raining tomorrow .........

easier answer still - pop the bonnet, and either get help, or you can do it yourself...

1) put the car to electrics

2) set the levelling from 4 to 0 or vice versa

3) run to the front and place your head / ear to each headlight assembly in turn.

4) each side should make a whine.

If each side makes a whine, you can start by just lubricating the mechanism, as its possibly as silly as a seized mechanism. If that fails, then look to replace, but I dont think you will have an issue, when you lubricate it up that should sort it out.

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Leveler_99-2001.5.jpg

Leveler_2001.5-04.jpg

Here are the wd's for the levelling, the difference between them is that the motor power is taken from the Low Beam on pre 2001.5 and from side/parking lights on post 2001.5 model years.

Hope they help.

yes cheers Dan thats a big help thanks.

Haynes schematics are not too clear.

I should have guessed that the power would come from the headlamp feed because they would only need to be operable with the headlights on doh!

ok I've done a bit of squinting at the electrical schematics in the manual and I think I have finally cracked it.

A live feed goes to one side of the leveling switch (which is a rotary rheostat)

The other side of the rheostat goes to earth

The centre tap of the rheostat feeds the variable power supply to both the headlamp levelling motors on a Blue/Red wire

I need to remove the 2xwire connector to both the headlamp motors and switch the ignition on and test I have a voltage .

if I have voltage then I need to check the earth to the motors is good.

If both the live feed and the earths to the motors are ok then the motor/s might need replacing.

If the earth is good but there is no power from the switch I need to check the 12v supply to the switch (when I can find where it comes from grrrrrrr)

It looks like it shares the feed from the headlamp washer fuse . (Diagram 10 Haynes manual)

If the motors and earths and rheostat supply is ok I'll need to check/replace the levelling rheostat or replace any defective wiring if there is a break somewhere.

Now if it will just stop raining tomorrow .........

good idea but unfortunately the MOT tester who adjusted my lights said that there was no indication that the motors were being powered.

I tend to use my multimeter for testing but I'll rope SWMBO in tomorrow and try that first ^_^