I just accomplished a similar endeavor and switched to a MP3 system. Got my "pocket" from St Charles Isuzu for $9.84 and included shipping. I cut and soldered my wires to the new system connector though and posted an existing (old now) wiring diagram from the CD manual on this site recently.

My antenna lead was too short also and I had to buy an extension for $5. Also, the dimmer lead is the one closest to the radio box (Red/Green) on the diagram.

Now I'm learning how to "rip" (not burn) MP3's.

Good Luck,

Randy