Thinking back to my 68 Nomad, I had to crawl inside and unscrew the access panel. It's going to be tough, and some of the screws will seem impossible to get at, but a flex extension with a screwdriver bit should work. Once inside, you can figure out what failed. If it's the motor, disconnect it from the channel, and let the glass down. At that point you can open the gate.
If your window channel is rotted out, you won't find another one. I bought one for a Suburban because it was still available from GM at that time, and modified it to fit. You may be opening a can of worms when you get inside. Be prepared!
thanks striperss ... ok so the glass will come down manually once the cover is off and the motor disconnected ... i'll try that ... oh and the channel is is fine shape ... let you know how it goes
Its been decades since I worked on one, but if I recall theres a safety switch on one of the latches that wont let the window work unless the tailgate is closed. This could be something check when you have the covers off.
once that access panel is off of the tail gate, you should be able to gain access to the wiring. I would check for power there and also at the switch. Trouble shoot the wiring and power on it first as it could simply be a switch or ground. If you have power to the rear window motor, it could be the motor itself. Not an easy job.
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63 Grand Prix -needs restoration, 65 Catalina Ventura 4 speed - resto almost completed, 66 Catalina Convertible - at body shop
