Have an aftermarket radio installed and would like to have it on without the key in the ignition. I have read a few threads saying the only way to do it is add a switch to manually turn it on.

So, I find a place for the switch, run the wires and do a test by "plugging" the wires in the adapter (red, yellow & black). I flip the switch to the on position and it's as if I put the key into the on position. The dash lights and all that other stuff came on...

Anyone else run into this problem? Has anyone successfully wired a switch to the stereo?