Is the tailgate locked? If not, lock it, and then it will be off.

When the light would turn off about 2" into rolling the window up, it was triggering the lock, forcing it all the way down. I would think that if locking it by hand doesn't fix the light, you need to go into the tailgate and clean everything real well. It could be a sticking lock linkage.

"A young man who does not have what it takes to perform military service is not likely to have what it takes to make a living." - John F. Kennedy

Proud owner of an 88 Montero (with a blown engine).