Power tailgate override

It should have a switch on the dash to make the window go up and down also. If it does, trace those wires back to the fuse box and see if you may have a blown fuse. I had a 64 Belvedere wagon with a power tailgate window. The dash switch operated it, and the ignition key into the outside bezel worked it from back there. I have a spare power tailgate off of an early B body laying around. I don't know if the motor works, or if they are even the same....but it's yours if you need it.