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OEM Fog Light Switch Wiring....


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Ok may be a simple answer, but recently I watched my brother short his nice amber switch out...

The back of the switch has 3 prongs, I have the plug with the switch and know the sequence, source (light) pwr, and grnd. I wired this up like regular fog lights and i get a light on the switch but the lights do not come on.

Do I need a relay? Would that solve the mystery?


72 2002 (Rusty)

72 Polaris 02 (My bro's)

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Not sure if you have a factory switch or something other.

Here is the body of my old write up about the factory switch:

There are four connections on the back of the fog light switch: “+”,”31”,”S”, “S”.

The “+” connection goes to a switched +12vdc source. This is the control that should only allow the fog lights to be on with the low beams and not with the high beams. A good source for this is the yellow wire from the high/low beam stalk switch.

I used a crimp-on 3M nylon t-tap. These allow you to use an insulated ¼” quick disconnect for the new wire.

If you wish to run high powered driving lights to be on with the high beams only; you may tap into the white wire from the stalk switch. Further more, the yellow/white wire is live whenever the low or high beams are on.

The “31” connection goes to ground. A ring terminal can be connected on the left-side mounting stud for the heater box.

The “S” connection (either one) will then go to your control relay.

On the standard relay there are four connections. “85”, “86”, “87”, “30”.

The control wire from the fog light switch “S” connects to “86” on the relay.

The opposite side “85” connects to ground.

Connection “30” will be the supply +12v. This wire should be of proper size and fused. Usually connected to the bolt on the + battery terminal. In the Haynes manual and on my car, there is a connector into the white wires for the headlights. I would not use this as a power source for fog lights as this wire is only live with the high beams on.

Connection “87” supplies power to the fog lights themselves. The fog light bodies are usually grounded to the car body completing the circuit.

A round hazard switch connector may be used with the fog light switch. It is just a matter of removing and reinstalling connectors as needed to match the pin out of the new switch. The individual connectors press out once the locking pin is depressed. I have a small screwdriver that fits in perfectly. Bend the locking tabs back out and you are ready to reinstall. Wrapping the wiring with cloth electrical tape gives a nearly factory finish. It looks much better than the standard plastic tape and seems to weather well. Cloth electrical tape is available from many hardware stores. You can sometimes find older, round headlamp relays from some salvage yards. I mounted mine right next to the stock headlight relay and could switch should one fail.

Steve J

72 tii / 83 320is / 88 M3 / 08 MCS R55 / 12 MC R56

& too many bikes

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