Headlights not working :(

[450Nick]

Yesterday (at long last), I managed to get my Chim driving properly on it's new GEMS ECU (and what an awesome piece of kit it is - more on that another time). During the change I've pretty much ripped out all of the engine loom and most of the dashboard loom to replace. Once thing I haven't really touched though is the headlight/hazard/fog light control box.

It seems however that I must have touched something as when testing the car, I noticed that the headlights and fog light now do not function, though curiously the hazard lights do. So the control box seems to have power, but no light. I've checked all the fuses and they seem to all be ok and I'm now wondering what else to try.

Any ideas? I guess a useful bit of information would be a wiring diagram for the control box so I can test the inputs and outputs are looking ok - does anyone have one? If not then has anyone got any good diagnostic ideas to try?

Thanks!

[N7GTX]

No help with wiring diagrams but on every car I know, the hazard switch is independent of any other circuit. They are always wired direct so that in the event of electrical failure they will still work.

[450Nick]

Ah that's a good point... Bugger. Anyone else??

[450Nick]

No one...??

[QBee]

If you mean rear fog light, it won't function unless the headlights are working on dipped beam. So I imagine your fault is purely with the dipped headlights.

On many Chimaeras the dipped beam is the fifth fuse from the left, 15 amps. So check that first.

There is also a dipped beam relay, top left or top next to left, depending on the age of the car. Check it's fully home.

You could also check the wires on the back of the headlight switch.

Edited by QBee on Tuesday 16th August 20:51

[Steve_D]

Have you checked that you have not twisted the ribbon cables. The cables and the connections at each end have a marking for pin one.

Steve

[Discopotatoes]

Check the earth point on the front chassis body mount bolt

[Steve_D]

The fact fog and headlights are duff then it does point to the control box.
The fog is a direct output from the box.
If you are happy you have not reversed/swapped the ribbon cables then next is the box.
Mine has power feed from fuse 6 and fuse 10.
It is earthed at the O/S tunnel top.
If that does not help I can send you a circuit diagram.

Steve

[450Nick]

Thanks Steve, my earth connections are definitely fine so I'm thinking it is likely to be the control box... if you have a circuit diagram could you please send me a copy and then I can work on a diagnosis... Thanks!

[Steve_D]

PM me as You can't do attachments on a pm but I can on the reply.
Do you have MS Visio? If so I will send the whole car circuit (12 pages)

Steve

[450Nick]

Steve_D said:

PM me as You can't do attachments on a pm but I can on the reply.
Do you have MS Visio? If so I will send the whole car circuit (12 pages)

Steve

Yes and yes! Thanks Steve you're a legend...

[Steve_D]

Seen the PM but I don't have access to the file until I get home tonight.
The circuit is almost complete now just missing some door mirror and door open info.

Steve