I have a 2008 Sport Trac, bought it recently knowing it had a dead factory radio. Replaced it with an aftermarket radio. Radio has power, all functions work, but no sound output at all. I've done half a dozen aftermarket installations in the past, using harness adapters soldered to aftermarket radio harness and insulated each wire. Speaker wires, power, ground, and illumination wiring done per specs.
I can't imagine all four speakers are bad! I would get something out of them, but no sound at all!
Am I missing something?

 

Something about this makes me wonder if there was anything wrong with the original radio.

As you know the radio is one of the modules in the CAN network. Need to verify all in the network are functioning. A capable scan tool should help to check all this out.

 

Hanky,
I bought the truck recently knowing the stock radio did not work, and wanted to replace it anyway with a more functional head unit.
While waiting for the new radio to arrive, I found two of the three fuses related to RADIO were blown and replaced them. Still no power to stock radio when turning on. The stock radio is dead.
UPDATE: I went to a radio install place, and the guy slightly altered my wiring job to also have the DVD operational, as it said onscreen that vehicle had to be in PARK to operate. Now I can use it at any time.
As for the sound problem, he diagnosed that ALL FOUR speakers were blown! Hard to imagine, but he proved his case by showing me with a scan tool that wiring to speakers was good, from radio to speaker locations. Then he rigged up a speaker of his own to show that there was infact sound possible, if only the speakers worked!
Needless to say I ordered 4 speakers and speaker adapters. Will be replacing all four when they arrive.
The good thing is that this guy was very familiar with Fords, and knew just how to tweak everything to work right.
It only set me back $60 for his service!
I'm happy now!