DEH-P3900MD - No audio output.

I recently installed the stereo in a 1992 F150 p/up. I took it out of a 1999 Jeep Cherokee Sport, that I am planning on sticking a new engine in later this year. It worked great, when using it in the Jeep. I have followed wiring diagrams., did visual inspections of speaker wires, to ensure they match wiring diagram, connections, etc. I am using the Pioneer speakers that were used with it previously, in the Cherokee.