2002 Chevrolet Malibu Car stereo issues.

I have a 2002 chevy Malibu. About 5 years ago I replaced the failing OEM junk delco radio with a new aftermarket radio. It worked great up until this past thursday when all of a sudden it didn't work. I pushed buttons and low and behold, the eject button and display buttons worked. When I called JVC they said that the yellow wire that I guess hooks into the ignition switch to allow the radio to turn on wasn't getting the signal. They said to jump the yellow wire to the red wire and if the radio works than that is the problem. I did that and sure enough it works. My question is, what do I have to do to get the radio working again without having to manually turn it off every time I get out of the car? I want it to switch off automatically when I take the key out of the ignition. Thank you for your time.