1996 ford explorer sport speaker harness does this car have a factory amp because i have this car but i didnt have the speaker aftermarket harness but i had the power i hooked the wires from the new stereo and put them in the factory speaker harness and i heard nothing but i did see a spare wire in the factory speaker harness could that be the factory amp turn on?
You'll likely have to replace the spider gears and axle gears all at once as they probably are ALL chewed up. I'd try Randy's Ring and Pinion online. or National Drive Train service or you could try E-Bay.
If both plugs from the radio were the same size, one gray and one black, then you do NOT have an amplifier. If you had the gray plug with visible wires and a small squarish connector with a metal outer shell, then you have what is known as the Ford Premium system and it's amplified. Aside from the speakers there will be a blue/white wire which you must connect to blue/white on the new radio or to the blue if there is no blue/white (this is very important). You do not need to bypass the amp.
