Headlight / Fog Light / Wiring Help Please

I recently purchased a 2004 C2 Cabrio. The fog lights are on all the time that the ignition switch is on and the headlights don't work except on the high beam flasher on the stalk. I replaced the headlight switch, and now the headlights are fine but the fog lights are still on all the time. In the process of doing this, I noticed there is a green/white wire coming out of the plug on the rear of the headlight switch that has been cut about 1/2" from the molded plug. There is no evidence of a green/white wire anywhere in the vicinity - in other words, I don't see the other end of this cut wire. So I have two questions; What is the green/white wire and what does it do? Anything to do with the fogs being on?

When looking at the wiring diagram for the 99/00, there are multiple green/white wires coming off terminal "NS" on the switch. Three to be exact. (2) 0.75mm wires that feed the rear fog lights, this is the power supply to the bulbs. The third is a 0.5 mm wire that feeds the indicator light on the switch itself to show that the rear fog lights are on. There is also a white/green 1.5 mm wire on terminal "N" of the switch. This feeds the relay for the front fog lights. It is a terminal 30 wire, which means it is battery power (unswitched). If this wire is cut, I can't see how the relay would stay on unless it somehow has been previously modified for daytime running lights. Has the car ever been registered in Canada? Is the wire you are referring to that is cut actually the 1.5 mm white/green wire (more like an 18 gage wire) or is it a green/white 0.5 or 0.75 (more like a 22 gage wire). Do your rear fog lights work? Here is the switch: It feeds the rear fog lights directly: And feeds the fog light relay to switch the on the fogs: And here are the front fogs:

I would also guess a Canadian car or someone that wanted DRL's and programmed it that way through PIWIS or PST2.

Yes, I believe it is the terminal "N" wire, 18 ga., and yes, it was once a Canadian car. I'm sorry, but I don't know what the PIWIS or the PST2 are, but are you suggesting the computer can be manipulated to keep fog lights on or ?? You guys are good - I should have mentioned the Canadian car thing.

It has the Canadian mod.....he's talking about the relay panels I believe. I saw something in the wiring diagrams for the Canook daytime running relay. I would just sell the car and buy a new 991 GT3. ;-)

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Geez, why didn't I think of that? Problem solved! So if it has "the Canadian mod" - how do I undo it?

Your fog lights get power via the fog light relay (position 12 at the relay panel at the driver kicker panel). The relay has the power side and control side. Both sides get power from the light switch via that "N" terminal. So it looks like someone has cut that wire to bypass the light switch and instead supply the power to the relay directly and independently. Fuse A7 sends power to the light switch. Lets remove it and see what happens. If the fog lights are still ON w/o this fuse, they are getting power somewhere else. You can also remove the fog light relay (leave fuse A7 in place) and see. That way you can see which original components are still on (and controlling) the fog lights circuit. What to do next depends on what you find. The best scenario is the fog lights are still using fuse A7 and the relay. You can then go behind the relay panel to check its wiring and see where that green/white wire went (normally it's connected to the "N" terminal of the light switch).

Great info, and the diagrams are helpful too. I'll do some digging on this and let you know what I find. Very odd that the wire would be clipped but no evidence of the other end of that wire anywhere?? Maybe it was pulled down to splice in to a hot feed somewhere to keep the fogs on.

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That would be my guess as well.

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Yes both are OEM programmers that can turn off the DRL programmatically.

Headlight housing is probably not seated into the electrical connection properly. Remove headlight and adjust the electrical connection until your problems go away.

Removal of fuse A7 killed both front and rear fog lights, which is probably a good thing. No time to investigate further for probably a week due to travel issues. Will check the relay next to see if there is an extra wire or look for the green/white wire tied into a wire that is hot with the ignition on. Thanks again for all the input.

That's good. I think removing the relay should kill the fog lights as well. The A7 fuse connects to the violet wire to the "NSE" terminal of the light switch, which will connect to the "N" terminal of the switch when you turn it to the foglight position. That "N" terminal then powers the foglight relay and the foglights. So the easiest hack would have been electrically speaking use a jumper to connect these two terminals. In that way, the switch is bypassed and the foglight will be ON whenever the engine is running.

I finally got to the back of the relay panel expecting to see some sort of jumper wire, but it all looks original factory back here to me. So, I the larger green/white wire at the switch has been cut off near the connector and I am unable to find any sort of jumper wire, yet the relay is hot all the time and the fog lights come on with the ignition switch. Ideas from here?

The black/white cable in your photo does not match the wiring diagram that Paul sent a few posts above. It should be a white cable. Someone must have wired the green/white wire in your photo to somewhere after fuse A7 and that black/white cable must be grounded somewhere.

I would agree with you but the connector for that black/white wire sure appears to be factory. And who uses color striped wires when doing a field mod? I am thinking that the difference in color code may just be the difference between the 99/00 diagram provided above and what was used on my 04 model. Perhaps a 04 diagram would answer that if I knew where to find one. I may have to seek professional help on this one. At least it isn't a critical issue and I have the relay removed so that the fog lights don't work at all. Thank you very much for your input on this!

I know what you're thinking but I checked the '04 diagram and it happens to be exactly the same as the '99 (the one Paul posted) for fog lights i.e., that wire on the relay is white per the wiring diagram. I agree the black/white wire looks stock but these wires are easy to find and a pro can make any mod look stock...I don't have a good explanation so I didn't comment further on speculation. I agree it's a good idea to check with a pro in this case.