wiring diagram for fog light switch 71?

[TRE Cup]

the online diagrams do not show the switch and relay for the for lamps- only the lamps and some of the wiring. can anyone help?
thanks!
dave
info@tremotorsports.com

[304065]

Dave,

I've never seen a factory diagram, but the wiring is very simple. The switch is a SPST type with two wires coming from the back. One terminal to switched +12v (red wire with black stripe) from the back of the gauges (this is only the control circuit so I wouldn't feel bad about tapping the gauge wiring) the other one to terminal 86 of a round relay mounted up next to the fuse panel. Relay connections:

85 Ground (use brown)
86 Switched +12v (control circuit for relay) (whatever color)
30 +12v from battery (high current) (use fat red)
87 NO- this wire to one terminal of both fog lamps. (fat, whatever color)
87a NC (ignore, cut this off)

(Dave, the colors are my suggestions to make this circuit easier for a subsequent mechanic to troubleshoot. Whatever relay holder you get, whether a Porsche round one or a DIN "Ice Cube" type- the wire colors will probably be different (gray, etc). Just make sure your wires go to the right number terminals- you may want to use an ohmmeter to verify what color wire goes to what number terminal.)

Other terminal of the fog lamps to ground (fat brown). A convenient ground is the wing nuts for the battery grounds just above the battery boxes.

You might also throw a big circuit breaker in the fat red feed from the battery to the 30 terminal on the relay.

Obviously you would conform to the German DIN spec set forth in the Bosch Automotive Handbook, both for the connections to the relays AND the wire colors-- brown for the grounds!

Good luck and don't burn the car down! Say hi to Herr Schmidt for me.

[Grady Clay]

Dave,

My ’70 diagram shows the ground side of the fog lights going the common ground for the headlights, turn signals, and horns – one left and one right.

It shows white with green stripe wires (one for each fog light) in the main harness. These go through the 6-pin connecters near the batteries. The diagram terminates with the legend “Nebelleuchten (SW).” It doesn’t show the switch or where the switch gets power.

Judging by this diagram, I would guess all the necessary wires are in the harness. Behind the dash, look for a red/something that has the rubber boot completely covering the connector. I’ll bet it is very near the breakout of the white/green pair of wires.

I see the same kind of arrangement for the rear "safety" light.

I don't see any sign of it at the turn signal switch or headlight switch.

Best,
Grady

[304065]

One more thing:

If you wire it like I proposed, you will be able to turn the foglamps on when the regular lamps are off but ignition is on. Very handy for covert operations. If you prefer to have the fogs on only when the low beams are on, hook one side of the switch in parallel with the green/white wire to the green indicator lamp on the speedometer. I'm 80% certain that will work, I'll check it for you this weekend.

Grady, very nice to see you back on "board!" Keep the shiny side up!

[Grady Clay]

Dave,

I think I recall an extra harness break-out in the fender wiring harnesses. It was Factory taped to the front fender harness between the headlight and the 6-pin connector. That might have started in ’72 but worth a look.

Thanks John.

Best,
Grady

[TRE Cup]

thanks guys! glad to get the right info

[RoninLB]

No yr listed in vol VI

[wallstreet]

QUOTE]Originally posted by Grady Clay
Dave,

I think I recall an extra harness break-out in the fender wiring harnesses. It was Factory taped to the front fender harness between the headlight and the 6-pin connector. That might have started in ’72 but worth a look.

Thanks John.

Best,
Grady
I am looking for similar information. (1970/ 911T) I see a taped section of wire harness coming from the under hood area into the under fender. Bundle is:

a set of wires for left fog lamps; also a set on the right side; wires on both sides are striped, tinned and taped; I believe they are a white w/grn stripe and a brown. Under hood they appear to change to white with green circular hashes. Maybe these are not fog lamp wires??? One power wire into fuse then two wires out and to right/left lamps???

a set of horn wires w/ push-on connects; also taped-up; and a double "pigtailed" horn wires w/connectors going to the only horn on the left. The right horn is not connected but when connected does not function. Why so many horn wire?

then a set of three brown/ground wires with a brass eye connetor all tape together with one larger brown wire coming out of the tape, acting as a ground and going to the screw clip holding the side marker lamp inplace. Do all 1970+ 911's have a ground to the rear side of the marker?


Then in the lower fuse box; the bottom fuse with the white w/ grn marked "fog lamps".

Are there unused wires under dash to connect to a SPST switch?

Do I need to add a relay under hood similar to the round horn relay?

Or do I install wires from under dash to a relay and mount relay next to fuse box? Why are relay black OR red?

What is the "six pin connector" and where is it?

[charlesbahn]

#20 is the optional fog light, #91 is the switch, # 85 is plug connection 6 pole, # 89 is common ground
rats- picture didn't load- title is too long- lets try again-

[charlesbahn]