electrical niggles - one light affects another

[xcentric]

Just failed MOT on electrical gremlins - both front sidelights and one rear light affected by the operation of another light (indicator I think, relying on MOT report at the moment). Any ideas what to check/how to check to resolve what the problem might be? Seems an odd one.

thanks.

[griffter]

Odd electrical problems are often earths. Check battery clamps are tight, check connectors to lights and any earths in the vicinity. Check bulbs are right ones too.

[BertBert]

I'm not sure whether you can measure the resistance to earth or not. I'm no expert, but I'd faff about with a booster cable connected to earth (on the battery or somewere you expect to have a good earth) to get an earth to the lamp areas and then measure ohms from the earth of the lamp socket to your known good earth.

Bert
PS then I'd expect to get an expert in, but you never know!
If it was a simple car like a Caterham, you'd know the earths to check!

[CampingGaz]

Seem similar when incorrect bulbs (ie twin filiment, instead of single filiment etc) are fitted/failing thus when activated, effectively short circuiting system. Sorry not a very technical description, but so easy to have it happen when replacing bulbs

Edited by CampingGaz on Saturday 17th May 13:44

[xcentric]

thanks for info. Took headlight units out, cleaned and wd40'd the contacts, checked all bulbs and reseated, put back. Not really any joy so redid that, and now we're fixed.....

:-)

[griffter]

Well done!