4 wires on Factory Fog light Switch? and Heated Mirror - 97+ Q?

What is the 4th wire? I rigged up my PIAA lights and it was three. I cant picture what the 4th is for.

My plan is to use the Factory switch for aftermarket lights later on.

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Also, Heated side Mirrors. is this a direct plug and Play set up for Electric powered Mirrors??

If there is a Light in the switch then the 4th wire is posibbly the dimmer switch wire. It turns on the little light inside the switch...maybe that is what you are seeing?







iratefla

Hammered said:

Also, Heated side Mirrors. is this a direct plug and Play set up for Electric powered Mirrors??

Click to expand...

Yep!! Wire is already there as long as you have the heated rear window. :cheers:

JeepinJeff said:

If there is a Light in the switch then the 4th wire is posibbly the dimmer switch wire. It turns on the little light inside the switch...maybe that is what you are seeing?







iratefla

Click to expand...

That would make sense, Thanks!

JeepinJeff said:

If there is a Light in the switch then the 4th wire is posibbly the dimmer switch wire. It turns on the little light inside the switch...maybe that is what you are seeing?

Click to expand...

This might help.

crystalship1 said:

Yep!! Wire is already there as long as you have the heated rear window. :cheers:

Click to expand...

Sorry to bring back a 2 year old thread, but I figured it was better than starting a new one.

I do have a heated rear window, and power mirrors, and would like to add heated mirrors. I know it's a direct plug and play, but (here comes the dumb question), how does it work? Is it like on some cars where it heats the mirros ONLY when heating the rear window, and the same switch controls both? OR, is it like some cars, like VW where they are on all the time, regardless of having the rear defroster on?

Mirrors heat with the rear defroster switch, if what I read is correct. It'd be easy to check- pull the door panel, turn on the defroster, and put a DMM on the connector.