Hi all, I recently installed an aftermarket subwoofer & amp with my factory stereo. I'm having trouble getting the remote wire to work properly.

My first move was to wire it to an add-a-fuse and plug it into the radio fuse, but it did not turn the amp off. I tried several other fuses and they too did not turn the amp off. I asked a car audio shop near me and the guy suggested I wire the remote wire to the ignition wire. I have done some searching and am not finding much. Would anyone be able to tell me how to get to the ignition wire and the best way to splice my remote wire into it?

 

Or if there is an easier way to set up the remote, I'm more than welcome to suggestions. I'm not trying to take out the head unit though, I've already put my car back together!