4-Runner Tailgate Window Problem!

I can make the tailgate window go down using the rocker switch in the console on my '92 Toyota 4-Runner, but then it won't go back up. It doesn't work at all with the key switch in the tailgate. When I try using the key switch in the tailgate, I can hear a clicking sound somewhere back there. Finally I took the inside tailgate cover off and jumped the window motor with a battery, and the window went up just fine and the motor sounds normal. This all started happening gradually, with both the front and back controls working on occasion, now not at all. I am told that there may be some kind of relay behind the plastic side panels under the side windows, but I'd be hesitant to try and pulls those off if that's not true, not to mention that it looks like it would be difficult to get them off. I know somebody out there has the answer. Thanks a lot.Car Repair Talk's forum.