1988 Suburban - Rear Window won't close

The electrically operated rear window on my 88 suburban won't close. Apparently it is trying as the heater fan slows down and the ammeter moves, when I try to open the window. Any tips?

my '88 had the same problem, but would finally close slowly after several trys. I took apart the panal cover on the tailgate to expose the motor, regulator and window tracks. I wiped off all the old dryed glops of grease, and re-greased the window regulator arm pivit points. I sprayed the window tracks with a synthetic grease. Works much better now.

do the lube avery where it moves

Make sure the tailgate is latching on both sides as well. There are contact switches that won't let you operate the window unless the gate is closed completely. I have seen them where one side does not latch properly.