Headlamps Help

[catretriever]

Can anyone help me diagnose my headlamp problem?

Symptom: Drivers side headlamp goes out when I switch to full beam, leaving just the sidelamp lit (although if I just flash to full beam the drivers side lamp remains lit at the dip position).

So far I've replaced the notorious headlamp connectors in the wheel arches as well as both bulbs but the problem remains.

Sorry if this is a numpty question...I have alot of enthusiasm but not much talent for this kind of thing

Any help much appreciated.

Matt

[tvrgit]

Have you checked the bulb? Main and dip use different filaments.

Edited by tvrgit on Wednesday 11th March 11:32

[Barkychoc]

tvrgit said:

Have you checked the bulb? Main and dip use different filaments.

I was really scratching my head on this and I think you're right - bloody obvious when you think about it!

[catretriever]

Yep, as I said, I've changed the bulb but still have this problem. What I haven't tried yet is swapping the bulbs over so I'll do that next. The weird thing is that on the faulty side both the main beam and dip beam filaments extinguish when I hit the full beam switch, so I don't think it can be the bulb.

I was wondering if there was maybe a relay involved somewhere...or failing that maybe something's wrong with the steering column switch, or perhaps an earthing issue????

[tvrgit]

catretriever said:

Yep, as I said, I've changed the bulb but still have this problem. What I haven't tried yet is swapping the bulbs over so I'll do that next. The weird thing is that on the faulty side both the main beam and dip beam filaments extinguish when I hit the full beam switch, so I don't think it can be the bulb.

I was wondering if there was maybe a relay involved somewhere...or failing that maybe something's wrong with the steering column switch, or perhaps an earthing issue????

No, wait, wait...

main beam and dip beam have separate bulb filaments - dip beam goes off when main beam comes on. so if one main beam filament is bust, then that bulb will go off altogether when you switch to main beam.

Flashing the headlamps is different - that flashes the main beam on without switching dip off, so a broken main beam filament would give exactly the symptoms you describe.

Main beam and dip use the same earth, so if one works, the other should.

The steering column switch will work both beams or none.

Relays will (I think) work both beams or none. Not sure about that, would have to check the wiring diagram which is at home.

I would start by checking the wire and connector that supplies "main beam live" to the lamp, using a voltmeter or test light. Then work your way back to the connector in the wheelarch - is it live there? If not, then go back to the next upstream component (the relay) then the switch.

I still think it's most likely to be the bulb or the last bit of wiring on that side though.

[Wiz]

Had a similar problem with the drivers side lights. It was the wiring in the back of the wheel arch connector. The circuit from the fuse/relay works both lights so if thats the problem both lights wont work.

Fitted new superseal connectors after cutting the wires back to clean.

[catretriever]

Thanks for your help chaps.

I traced the problem back to a loose connection in the back of the other Headlamp (nearside).

All sorted now. Hurrah!