Rep Power: 0

the guy who owned my car previous to me botched the install of the cd player. the cd player/radio doesnt turn off when the ignition is turned off. I have to manually power it down every time i get out of the car. at some point i am sure to forget and run the battery down. I expect to find a missing ground wire when i open it up, but i'm not a real genius when it comes to wiring. what am i looking for? does that sound like a decent guess?

 
Rep Power: 308

If aftermarket he most likely tied the "switched power" lead to the "constant power" source.

Most switched power leads are red with an inline fuse holder & constant power/memory is yellow with a inline fuse holder also. (yours may be different depending on brand)

I had mine wired like that for a short time, then switched it back. Never knew if I turned it off or not.

 
Rep Power: 0

I used to wire my stereos to a constant 12v source so I wouldn't need a key to listen to the stereo when working on the car. But I have accidentally left the radio before and ended remembering after many hours when the battery is dead.

 
Rep Power: 253

This is more then likely what the case is. Many people don't realize that there is two different wires. One constant and one with ignition only. Its really easy to fix. All you need to do is undo the ignition wire from the radio from live at all times and connect it to the ignition wire that is hot only when the ignition is on. Its really that simple.