Audio Systems: 1988 Ford Crown Vic wagon, ford crown vic, home depot

Question
I'm installing a after market kenwood cd into a 1988 crown vic. I used harness connedctors to wire them up. I get the head unit to turn on and functions work but I dont get any sound even at high volumn levels. The one strang thing is it has a 10 gauge red wire with a ring terminal that fit on the stud on the rear of the stock deck. The wire looks like a factor install. Could this be the ground for the external amp?

Answer
wow, that is weird!!  hmm.  well, red almost never means ground,  it usually means hot/postative.  if you have the orriginal stereo I would look it over, if that stud that sticks out is isoloated from the body of the unit(plastic rings, that hold it, or something not metal) than it's probably posative, power to an external amp.  if it's obvious that the stud makes metal to metal contact with the exterior of the old unit than it may be a ground.  your best bet really is to hook the old unit back up and put a meter on it to see what that stud provides, wether it's ground, or contant power or "triggered/switched" power, etc.
If you have a meter I can definatly help with how to do that if you need help. if you dont have one you can get one at any auto shop or walmart or home depot.  mine was only 20 bucks and works great so dont spend alot.
Good luck and let me know how it goes!