Additional Tailgate Troubleshooting

Hey there guys, after much reading and several attempted fixes I am at my end to try and figure this out.

I have a 1991 4Runner where, like others, the tailgate failed to lower the window.

I tried the wiper bypass; I have tried the 1st gen switch bypass in the console. I have replaced the relay box with both options from working donors. I’ve checked continuity from the relay to the motor, that passed. The truck came with the wrong relay in there; one from an 89 so with the proper relay I get some progress.

With everything wired to factory, the rear wiper works, wipes and returns home, and the key will return the window UP after I manually lower it with power directly to the motor. The interior switches do nothing and the key will not lower the window.

If the tailgate is open and I attempt to use the key to raise the window; it gives me the 3 beeps so the latch sensor is working. The light on the dash illuminates when the lock is opened to release the tailgate, so that contact is good. I’m running out of places to look or things to try.

Any thoughts or other things to check would be appreciated!

 

Is the tailgate actually locked? I know the window will not go down if it is unlocked. Maybe the motor is not getting the signal that the door is locked.

 

The mechanical latch that can be pulled up when the window is down? I can see it if that makes any difference though I thought that sensor was just for the rear door light on the dash, unless there’s another sensor for actually locking the back door?

 

The light on the dash is to let you know the rear door is unlocked. Yes, the mechanical latch on the door itself. Make sure it is down. Light should go out and that should let your window go up. Sounds like you either have a switch issue or wiring issue.