ford expedition stereo conected directly to battery wont turn on

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my friend was installing it when je noticed tjat the actual harness was missing just the ground,positive and two speakers were conected so he said lets see id it works


From what I can understand of this post it seems you bought something that the last owner did a hack job on. Are you saying that the deck that was in it when you bought it was installed by someone who hacked up the wiring harness and cut off the plug? Any chance that this has a premium sound package on the factory setup? Not sure with these ones but do recall some vehicles with a factory premium sound package had a separate amp in them. When you put in an aftermarket deck you had to unplug the harness in it because you won't be using it anymore, and you put a wiring adapter on to allow you to hook in your new deck.

Either you have something as I had described, which I don't think you do, or that plug was cut off. You may have to pull a few things out of the dash to help you find where it is, but its in there. Remove that splicing/ hack work and make repairs to whatever on the factory wiring was damaged. If the factory plug was chopped off you'll need to go to a salvage yard or something to get a pigtail to install. Do not just twist the wires together and tape them, it needs to be soldered and then covered with heat shrink tubing.

If this is out of your knowledge and ability to do, you should take it to a pro who can. I will tell you right now he isn't going to be pleased. I get pissed when people hack up their wiring cluelessly and then ask me to fix the damage. So it will cost some cash to do this right so nothing in the truck gets fried. I have seen people do things just like this that resulted in the car starting on fire and being totalled. As such, it really needs to be done properly.