I just installed my subwoofer and amplifier (under seat) but i'm having trouble finding a reliable source that'll keep the amp on but turn off when the stereo is off. This is tapping into the stock radio harness. I have tried.

1. 3rd wire from the end (Power antenna wire i believe) Turns on amp when radio is on but amp turns off when mp3/cd is playing.

2. Tried 2nd position from the end next to the illumination wire but there's no wire coming out of that position on the harness (just inserted in to see what would happen). Turns on when radio and cd is on but amp doesn't turn off when i turn the head unit off. Amp is on when it's on ACC and ON in the ignition.

I may just put it into the 2nd one and keep it that way. Any suggestions??

Tj, use the gray wire, I did vegasscion Xb and I noticed the same thing. Also use the front speaker outputs the rears have an amp that I can't locate yet. Watch yout ground take the time to remove all the paint around two inches from the center to assure a good ground. also make your ground short as possible. Bill

Well i got impatient with getting a reply so i did option 2. Got the wire to make good contact and zip tied the remote wire. My 10" kicker sounds great in the scion. On my spare time i'll install an inline switch to switch it on and off or i may do what you said. I don't wanna stay out in the garage to long .. it's 41 degrees.

Tj, use the gray wire, I did vegasscion Xb and I noticed the same thing. Also use the front speaker outputs the rears have an amp that I can't locate yet. Watch yout ground take the time to remove all the paint around two inches from the center to assure a good ground. also make your ground short as possible. Bill

The rears have an amp?!? Really?

use a signal generator and try to run tone through them with no power on the harness, remove the plug at the head unit and try it tell me what you get. Don't do it at the speaker. I could be wrong, but tone generator worked fine on the front. Bill