I have an 89 Bronco and the switch to roll the rear window down doesn't work. I can roll the window down with the key but we lost the key and until I can get replacement I need to figure out how to roll down the window with the switch.
We checked schematics in a haynes book but they are way off. All I can say is that the fuse is fine.
Take off the back panel to the tailgate take a flash light and look at were the key switch comes into the tailgate.
When the key is turned a lever hits the button to make the window go up or down depending which way you turn the key.
You might have to take off the lever to push the button to make the window go down.
If you push the button for down and the window won't go try hot wiring the motor with 12v.
If motor still won't go motor is bad I never seen a window motor go bad yet.
After you take off lever from window lock you can take off spring clamp that holds in lock and take it ot a locksmith to have a new key made.
For switch bypass it. It is just a rocker switch If you bypass it and window works switch is bad.
First take off tailgate cover and make sure motor works.
Take the switch out of the dash and take it apart. Chances are that the problem with the switch is that from the contacts arcing (which is normal), they aren't making good contact anymore. This happens alot on door switches for power windows and power door locks. I had the ones in my '88 bronco and my '88 F-150 out 100 times. Take the switch apart and GENTLY file the contacts down with light sandpaper or a fine nail file until all the black arc marks are gone. Good as new.