I had the same problem on my 89GT. The stock amp is directly behind then below the radio. What you have to do is find the wiring harness that is before the factory amp. Plug the aftermarket wiring harness into that, and it will work. I found the wiring harness up behind heating controls. Good luck!
__________________ - Doug
89 GT 5.0 AOD,TFS Street Heat intake,TFS TW heads, TFS stage 1 cam, 1" phenolic spacer, 1.6 TFS RR, 65mm TB,24 lbhr injectors,Kirban adj. fuel pressure reg.,C&L 73mm MAF,PA Street/Strip Valve Body, MAC CAI, BBK shorty headers, off-road h-pipe, 2-chamber Flowmasters, MSD 6AL, MSD coil, 4.10's, 190 lph fuel pump,BFG Drag Radials |