wat is this gain for.. it isnt in my iroc. the radio is aftermarket. nothign good just wat came with the car.
Thanks
Shaun

 

That switch is for the factory baby subwoofer.

 

I have the same thing in my car. when I first got it,it had some crappy toshiba tape deck. I already knew it worked ok,but when I got the car home,I wanted to see what the button with the "music notes" on it did. as soon as I pushed that button,my car was filled with smoke from the HU,someone had wired it wrong or it just wasn't meant to be used with GM's sub system. I had to remove the switch and jump the "norm" connections together, and clip the pins for the "sub" connections. I put the switch back only for looks,it did nothing. the amp is under the pass. side dash cover,small sheet metal box approx. 1"thick,5"x5".....no labels,just a small two wire harness w/yellow and grey wires (from switch) and a larger plug with some blue colored wires and some other colors,these connect the radio and speakers. I wouldn't go through the trouble of re-wiring everything,but I'd disconnect that amp and run the necessary wires to make an aftermarket HU work. using the mini sub boxes in the sail panels might work out for you,sometimes I wish I had kept mine....