Mustang Radio into Lincoln TownCar...

Hello, after I sold my 97 GT to get a cobra, I bought myself 1991 Lincoln Town Car for $900 (winter beater with style ). It had some problems, but I have just about fixed it all up.
The radio wasn't picking up any FM signals. We tested the radio with another antenna, but it still didn't pick anything up.
Here is a pic of the old radio:
http://cgi.ebay.com/ebaymotors/1994...ewItemQQcategoryZ38639QQitemZ8000452873QQrdZ1

So, staying on a budget, I got a radio out of a 1994-2000 Mustang from ebay because it looks a lot better than the crappy stock one: http://cgi.ebay.com/ebaymotors/94-0...998124820QQcategoryZ38639QQrdZ1QQcmdZViewItem

The plugs are all the same, and the radio slid in fine, but now I'm not having any sound through my speakers. The radio is showing that it's picking up FM stereo, but I'm just not having any sort of sound through my speakers.

I'm figuring that the wiring of the two radios is slighly different, although it plugged right in. Does anybody have any idea how to make this new Mustang radio fire up my sound system in my Lincoln? My Lincoln has a JBL amp in the trunk, like my old 97 Mustang with the Mach system had.

Maybe anybody with a wiring diagram from a 94-00 Mustang Radio would be able to help out?

Thanks!

After some help from a different message board, I found that the newer radios only put out 5-6 volts in the "amp enable" pin, but the older ones put out a full 12v to fire up the amp.
I jumped the amp enable with another wire to give me 12v when the radio is on, and I can finally hear some sound.
But the sound is very faint and high pitched, even at full volume. It sounds like my 97 GT used to sound like right before the amp would kick on.

By jumping that pin with 12v, I have sound, but it sounds like my amp isn't kicking on. Any ideas how to get full sound out of my new radio?

Thanks!

any ideas?