[theorio1025]

Im working on a 1990 mustang gt, instaling a radio. I wired in the plus in harnesses to the radio, and the radio powers on fine. There is no sound coming form the speakers however. When i plug the factory radio back in they work. I followed the wiring diagram exactly, and still have nothing. Im new to mustang stereos so is there something im missing. The harness in the car only has 5 wires, wheres the old radio, and new harness have 8 pins.

[wildstang803]

there should be 8 wires in speaker harness. Its strange they all work with stock, seems like it would almost have to be in the wiring in the car, I recomend running all new speaker wire, it is a 90, the get old,fall apart,short out. etc. it wont cost but 20.00 at the most, hey its you car, run speaker wire everywhere,lol. I found it easy yo go under backseat and around driver door into the back of radio housing, not to hard at all

[theorio1025]

thats what i was thinking of doing but i figured id see if ford was still using a common ground in that year.