Headlights again

My headlights are not working on either normal or main beam. The side lights work no problem and the "flash" on the indicator stalk works no problem so I know the bulbs and earths for the lights are fine.

I know their are many threads about this and it seems to be a common problem. However I do not know what wiring I actually have as I had a "300tdi" bulkheadcomplete with dash fitted during the rebuild when my chassis was swapped. The first thing I need is help identifying what year this may be to identify the correct wiring diagram.

The steering column switches that I have do not have bullet connectors instead they have white multi spade connector plugs. and the headlights only work when the ignition is turned on. This leads me to believe it is the later 300tdi wiring loom in the bulkhead.

The fuse box and relays are shown here:



If any one can confirm which wiring diagram I should be looking at that would be great.

Moving onto the problem I have currently.

Side lights work fine but if you move the headlight switch to the second position the headlights do not turn on. I have checked with the multi meter that the switch is working and I am getting power out of the switch (blue wire). I have checked the relay in the fuse box with the blue wire (center relay) and this is also working and you can feel/hear it click when the ignition is turned on.
Can anyone help me with the next thing that I need to test? Reading other threads a lot of them talk about the dim/dip relay. What is this and what does this do? It is described as a pink relay behind the dash binnacle but I cannot see anything in that location on my vehicle.

Have you checked the green fuse in the engine bay fuse box?

Pic here

mojo247 said:

Have you checked the green fuse in the engine bay fuse box?

Click to expand...

I haven't no, is that on the passenger side next to the heater box? I will check that in the morning.

A dead dim-dip relay shouldn't affect main beam operation so main and flash would work.

Kwakerman said:

A dead dim-dip relay shouldn't affect main beam operation so main and flash would work.

Click to expand...

So because I don't have main beam or normal headlights it is likely to not be anything to do with the dim/dim relay and I can eliminate that as a source of the problem?

dag019 said:

I haven't no, is that on the passenger side next to the heater box? I will check that in the morning.

Click to expand...

Yes, when mine stopped working I spent ages looking about trying to find the fault but then someone pointed me to that (which at the time I didn't even know existed :/) and it was burnt right out.

Might not be the answer but worth a look

dag019 said:

So because I don't have main beam or normal headlights it is likely to not be anything to do with the dim/dim relay and I can eliminate that as a source of the problem?

Click to expand...

Never say never but I would be surprised if it was the relay, when the dim dip relay dies it is normally because the plastic that holds the relay contacts in place melts and you loose the dip, I don't think main beam is affected.

mojo247 said:

Have you checked the green fuse in the engine bay fuse box?

Click to expand...

I have checked this fuse and it has not blown.

What else could be causing the lights not to work?

How do I check the indicator/main beam switch?
Is this likely to be an issue, it appears to be a common failure point on similar problems?

Having been unable to work out how to test the indicator switch I took the gamble of buying a new one (genuine Lucas) and this has solved the problem so I have working headlights again.