Fog Lights switch on and off automatically

[H3Eric]

Hi,

Did anybody have the problem that the fog lights go on and off automatically while driving. The dealer could not find immediate the problem and I was wondering if anybody has had this before. It is irritating to the other drivers on the road since they think that I'm blinking with my lights :-(

By the way this happens only when the fog switch is on.

Thanks,
Eric

[stagger_lee]

Never happened to me, and have never read anything about it happening on here. Sounds like a loose connection somewhere, fuse maybe?

[wpage]

If it occurs only when lamps are turned on. It means the circuit goes into a open state. This can be a poor connection or faulty switch. Trouble shooting a occasional problem requires patience. 1st try isolating any apparent areas for simple things like loose connections, cold solder joints, broken swinging sections of conductors. Last test switch for continuity with ohm meter under differing conditions. Like hot cold temperatures. Or does this occur on bumpy roads etc. Good Luck

[H3Eric]

stagger_lee and wpage,

Thanks for the replies so far.

I guess I will start with cleaning and following the wiring and looking for obvious issues. The dealer did this as well and could not find anything. I'm wondering if the internals of the relay is weak and during bumping just flips between the two positions.

I know that both lights do it at the same time (on and off) so it is probably nothing with the indivudual wiring to the actual fog lights.

Regards,

[stagger_lee]

Sorry Im not much help, but maybe follow one of your friends in different road conditions and see if both lights do it at the same time, and if it is directly affected by bumps like wpage said. Any info you can feed the dealer will help expedite their services. I hate electrical BS

[evldave]

Another couple things to look for:

The fog lamp switch is wired w/the headlight circuit - if the headlight switch is in AUTO and the fog lamp switch is on, the fog lamps should only come on w/the headlights. Are your headlights also going on/off? If so, it could be part of the light sensor circuit - check the little round dohickey on the dash to make sure nothing is covering it. If it's clear, and the headlights keep going on/off, there might be a problem in that circuit.

Turn the headlight switch to ON. If thefog lamps still go on/off, then it would likely be in the wiring for the lamps themselves, not the light sensor.

Also, check the little light on the fog lamp switch - is it going on/off? If it's staying on when the lights go off, it's likely a wiring problem after the switch. If it too is going on/off, there is a problem in the circuit before the switch. Look up evldave in webshots, I think I have a wiring diagram of the lighting circuit, that might help you figure out where the short/problem might be (can't remember now which diagram I have and work won't let me view webshots ).

Good luck!

[DRTYFN]

Originally Posted by H3Eric

stagger_lee and wpage,

Thanks for the replies so far.

I guess I will start with cleaning and following the wiring and looking for obvious issues. The dealer did this as well and could not find anything. I'm wondering if the internals of the relay is weak and during bumping just flips between the two positions.

I know that both lights do it at the same time (on and off) so it is probably nothing with the indivudual wiring to the actual fog lights.

Regards,

My money is on the relay.

[H3Eric]

Evldave, thanks for the excellent suggestions. The head lights stay on so I guess I can forget the sensor but I didn't think about the fog light switch light yet. I will take a look at it as well.

DRTYFN, depending on the outcome of the research of the switch I will start with the Relay, it is the easiest thing to do anyway.

Thanks, I will update you guys when I find it.
Eric