Chasing down a non-working fog light problem...

[madsedan]

I bought the car with no fog lights installed so after the new bumper cover I put in the fogs and neither one lit up but the bulbs appeared to be ok. I bought a new pair of bulbs and now the driver's side works but not the passenger side. Both fog light fuses appear to be good and I can't see any cuts in the line so how do I figure out whats wrong?

[12:03]

no clue thats a good ?

[12:03]

is it M3 or 3 series. what do you mean about you bought it with no fogs? did you buy them, was your car pre wired, Im confused

[madsedan]

Its a 95 M3 and it was wired for fogs but the guy bought new ones and hadn't installed them. I had to trim the plug a little to get them into the socket on the fogs so maybe they were from a 96+ or something but the driver's side works perfectly.

[Jim O.]

Get a meter, and start checking voltages. If you have voltage at the connector, then check the ground for the light. If you don't have voltage at the connector, then start tracing it back - check for voltage at the fusebox, at the switch, at the relay. Get out your Bentley, and follow the wiring diagram to find out where the problem could be...

Jim

[madsedan]

OK, thanks. I guess I need to buy a voltage checker thingy.

[12:03]

JIM is so wise. thats what i meant to say get a volt meter and find the power loss

[madsedan]

I figured that was the case but I was hoping maybe a couple had run into that problem and could narrow it down to one or two spots. I have a new light switch in the car so its probably somewhere between the fuse box and the fog light.

[Loud_TIGER]

same thing happened to me. all of a sudden my passenger fog light won't work. new bulbs in both.