Here's the story, I have a 00 Si that I brought here to the UK, UK law says you have to have a rear foglight due to the climate. I'm not too keen to drilling a hole in my bumper or altering a taillight so I did what most converters do: I am installing an aftermarket one.

I want to tap into the factory foglight switch so when I power the front fogs, the rear fog will come on. There are three wires on the back of the switch: black = ground (duh ), red & white, and red & yellow. Does anyone know which of the red ones is the signal to lamps?


Sorry so dirty...been raining here last two days go figure?

 

it looks like one is 12volts in and one is 12volts output..
put a meter on it and test it, ground to black and then
with the ignition turned on see which one has constant
power and which one is switched by turning the switch
on and off.

still sporting the massachusetts plate?

 

Yea, just use a meter or a test light... and see which one gets power when you want, and that's the one to tap.

 

to a nice guy and a bad *** si