fog lamps operation

[Roby466]

I just got a 1985 930 and I was going through the electrical butchering that was done by various alarm and radio shops (pretty surprising what they can come up with for a ground (12V live wire??) so I always go through that when I get a new old car.
I noticed that the fog lights work regardless if the car is running or not as long as the headlight switch is pulled to the first stop or more.
I looked at the wiring diagram and while my sc's switch took its signal from fuse 6 (low beam), the 1985 Carrera and 930 takes it from fuse 2 (license plate light) so they work as long as that is on).
Is the diagram AND my car wired wrong or are yours the same?
Thanks
David

[Joe Bob]

Stock fogs should only work with the headlights on and in low beam. Some people use them as daylight running lights and change them to on all the time wiring.

[Sabre]

check to see if you have a 2-stage switch. turn the switch to the left and make sure that it is pushed in.

[schumicat]

This is correct for US cars, but I think Canada had a different set up. There are wiring diagrams on Pelican's site - they have a whole separate diagram for the fog lights that shows the ways different countries are wired (because of different laws re: when you can/can't run fogs).

Originally Posted by Joe Bob

Stock fogs should only work with the headlights on and in low beam. Some people use them as daylight running lights and change them to on all the time wiring.

[86 911 Targa]

Originally Posted by schumicat

This is correct for US cars, but I think Canada had a different set up. There are wiring diagrams on Pelican's site - they have a whole separate diagram for the fog lights that shows the ways different countries are wired (because of different laws re: when you can/can't run fogs).

Would you have the link for the diagrams?

Thanks,

Gerry

[Joe Bob]

My euro delivery was set up like that. Along with headlight replacement with DOT units, the Feds had them rewire the fogs.

When I went to the backdate, I lost the fogs and just left the switch.....

Bentley, while flawed has some of the better wiring diagrams, as do this site.

[Roby466]

I got the car from the us, it is a grey market car so was originally euro.
If I look at both bentley and haynes, their diagrams would make the fogs work as soon as parking light work... regardless if the ignition is on or off... these diagrams are sometimes weird though.

[schumicat]

click on the "new parts catalog" tab at the top of the page, and look on the left under "features" for "elec. diagrams" and click there.

Originally Posted by 86 911 Targa

Would you have the link for the diagrams?

Thanks,

Gerry

[OSI930]

Check out this link:
Running Fog Lights only....

[Canada Kev]

I believe that the fogs are typically only supposed to come on when the low beam head lights are on. Regardless whether that's true or not, my RoW car was like that, but I wanted it so that I could run the fogs without the head lights.

If yours work at any time the running lights are on (headlight switch at first stop or more) and don't want that to be the case, then follow along to read how I changed my fogs to operate differently.

I did the moving wires on the fuse panel thing without success, and was a bit stumped as it had worked for others. Then I thought about it some more and had another idea: I just moved the fog light relay trigger wire to a terminal on the headlight switch that was powered when I wanted to run the fogs.

Previously, I had an issue with my headlight switch and wanted to know what all the terminal pins did on the back. I did up a matrix to determine just that:

Handy headlight switch matrix:




According to my wiring diagrams (remember it's an RoW car, so it may not be the same for yours) the fog switch will allow current to go to the relay whenever it it switched on AND has power to send. It gets this power from the headlight switch, and it gets it when certain parameters are met: when the headlights are on, when the running lights are on, when the key is on... These parameters are determined by the placement of the wires on the headlight switch.

In order to do this, I just moved the GREY wire (fog light) from terminal 56 (yours will likely be one of the 58 pins) to terminal 75. I initially used terminal 58 so they would work only when the running lights were on, but I found that if I forgot to shut the lights off, the fogs would still be on due to the fact that these cars willl run the parking/running lights even if the car is off and the lights are still on. The fogs were on this circuit so they would remain on as well and quickly drain the battery. This wouldn't work for me. I then moved the wire to terminal 75 so the fogs will be capable of operating at any time the ignition switch is turned on.

Keep in mind that the fog light switch will still need to be on in order for the lights to work regardless of which terminal they are connected to on the headlight switch.