Tail gate will not open

Loose most of the way, then it gets tight near the very end of the pull. It acts like a cable or wire has suddenly stretched to the point where it will not disengage the latch and since it has been sitting for almost twenty years I do not know how that could have happened. I guess I will need to remove the inside panel and inspect the situation. I thought possibly there was a switch that would not allow the door to open unless the window was completely down and since I know the window is completely down perhaps the switch, if any, is defective. Do you know if such a switch exists and if so, where is it? Thanks.

Thanks worked perfect you were right about the bushings, I just bent the rods a little more and everything works great.