Help with a fog light switch

[speednme1]

Hello gents, I have this rear fog switch on my 77 Porsche 930. I have the factory loom for the rear fog light and would like to wire it up but not too sure what the prongs on the switch are. The switch appears to be a 914 item though it looks very stock in my 930. Attached are pics of the switch and the location of the switch in my car. Any help would be grateful...as I’ve done an extensive search on the web but have come up kind of empty.

[Dave at Pelican Parts]

Umm, it's a switch. When it is pushed in, the two wires plugged into it will not be connected to anything. When it's pulled out, the two wires plugged into it are connected together. (And the light in the switch comes on.)

In a 914, the switch gets powered by one of the low beam (for fog lights) or high beam (for driving lights) fuses. Then the other wire goes to the lights, then to ground. This ensures that the lights come on only under the correct circumstances. You can, if you wish, power the switch from a switched power source instead so that you can turn them on any time the key is on.

I do not recommend confusing switched for constant power, because it is too easy to forget them and drain your battery. Don't ask how I know that...

--DD

[gruntie]

......plus the 3rd terminal would be an earth for the switch itself (poss labelled ‘31’). A multimeter or test light would sort it out.

[speednme1]

Thank you gents.

[skinnerd]

On your switch, the following:

terminal 31 is for ground, this just grounds out the bulb in the switch that illuminates the switch cap when the fog lights are on

terminal K is for power out to either the fog light or fog light relay; since this is for a rear fog light you'll likely not be using a relay

terminal 15 is for power in; can be either switched by key or always on power, your choice

I've got this exact same setup for my 914-6 with a rear fog light.
They work great.

[gruntie]

To be rather pedantic - nay, anal - the switch insert shown is for front fogs. For rear fogs, you should be using this one. Though I don’t suppose it matters.

[skinnerd]

I've seen a lot of early 914's with just the green fog light switch vs the carmel colored one.
Mine is a 71 and that's how it came.
So maybe it's a year kind of thing or Porsche/VW just put in whatever they had available at the time.

[speednme1]

Thank you gents for the help. I did also find a link with the actual instructions on a VW van blog(go figure). Looks like the switch may still be available but now with a VW part number. Anyway here are a few pics. All the factory wires/loom were there for the rear fog light including an empty terminal for the ground and on the factory light switch (terminal 56..low beam headlight)

[skinnerd]

Well done by speednme1.
Looks great and will massively improve your visibility to following drivers.

[speednme1]

Originally Posted by skinnerd

Well done by speednme1.
Looks great and will massively improve your visibility to following drivers.

Thank you