quick wiring question

[Hugh]

I got a couple of those round dash button switches from a 320i (a green one and a purple one) at the junkyard this weekend. I used one to wire up the manual overide for my elec cooling fan.

Question: How does the wiring work for the switch to light up?

There is 1 green wire (I wired it to power)

There is 1 black wire (I wired it to the fan)

Fan overide works great...

There is one terminal with 2 brown wires (I figured ground but when I grounded these wires the light did not work)

Anyone know how these switches should be wired?

THanks!!!

[Hugh]

the more I think about it, it HAS to be ground to the brown wire. I must have a burnt out bulb.

[SteveJ]

From my write up on fog lights:

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.

[Hugh]

Thank you very much Steve....much appreciated.