So my car was stolen a while back but only the stereo was missing when i got it back a week later (lucky I know). Anyway, I finally got a new stereo but there is something wrong with the ignition switch power. I checked the wiring a hundred times and I have put in a stereo in a couple times before. It gets power when I plug it in but doesn't come on when I turn the key.
Any ideas?

 

accesory wire?

 

The thief may have pulled the pin switch for the power source when he jacked your radio. With the engine off and the key in the run (ii) position, check for voltage between power source for the radio and chassis ground.

 

It sounds like the accessory wire does not have power. You should have power at the wire (yellow/red) when the key is in the ignition II position and no power when the key is removed. Check the fuses in your dash, the radio usually shares a fuse with the cigarette lighter.

The other power wire (white/yellow or white/blue) is "constant" and always has power to keep the memory etc.

http://www.installdr.com/Harnesses/HA-Wiring.pdf

 

check your under dash fuses. is your dome light and ciggy lighter also not working?