The factory stereo in my f 150 went to down the drain. I am installing a new deck. The problem is ford never seemed to have a standard on their wiring back in 91. If anyone knows what color coded wires are which it would save me lots of time.
all l can say is good luck. l figured out the wiring in my 89 f-150 just by trial and error. blew a couple fuses, prayed a couple of times that l didn't burn up anything else, and finally figured it out. l think l remember that a couple of wires were basically the exact same color, l think it was orange/black. but then again, the red/black could've just faded a lil over time. but like l said, good luck.