headunit in 2002 chevy trailblazer

How to retain door delay for your radio on GM

The RAP (Retained Accessory Power) relay is in the driver's side fuse box.

Pull the relay halfway out, so it still operates, but you can carefully slide a test light or meter against the terminals.

Test the terminals until you find the one that operates correctly. I think it is terminal #30, but not sure. If you don't have a tester, you could connect your amp turn-on wire to each terminal and try each one until it works right...it would take longer this way, but you won't hurt anything even if you get the wrong terminal.

After you have identified the right terminal, wrap a wire around it and reinsert the relay. Connect a small inline fuse---1, 3, 5, 7.5 amps----whatever you have on hand. Then connect the amp's turn-on wire to the other side of the fuse, and you're done.

The reason for the fuse is so that if your amp-turn on wire shorts out sometime in the future, the fuse will blow and of course your amp will shut off, but at least the rest of the car's accessories will remain operational until you can repair the problem.

Also, the RAP relay is probably protected by a very large fuse, which might not even blow out if your wire shorted...meaning your wire would melt and possibly catch fire.

So I'm not trying to frighten you or anything, just be sure to put that fuse inline right near the RAP relay.