I've rarely had electrical problems with my car, but all of a sudden the CD player wont turn off! It started last night. I took the key out and the music didn't stop. When I pressed a couple of buttons on the CD player, there was a loud *thud* from all speakers at once. Sounded like a high voltage static pop. I ended up just pressing the power button to shut it off.

Otherwise, it seems to be functioning properly?

Any idea where to look for shorts other than directly behind the head unit?

 

Could be the ignition switch. Does other stuff that should cut off with the key (wipers, turn signals, heater blower) stop when you turn the key off?

If its an aftermarket CD, the red wire should turn on and off with the key. If there's no voltage to the red wire yet it continues to play, the CD player is likely defective.

 

Everything else does stop. Engine, wipers, blower. Inside lights pop on like normal. The only difference I can see is that the CD player doesn't turn off.

I'll check the red wire. It's aftermarket, and I've been running the same Alpine CD player since 2005.

 

We had the same issue a few years ago. Even with the key out the radio/clock were saying on. We ended up just pulling the fuse to them as we couldn't figure out any other way to get them off and didn't want the battery to die.

 

That tells me that there may be a wire with worn/damaged insulation, allowing it to contact an always-live wire. I'd start there.