Ok so i have a 94 bronco and would like to fix my back window. The dash board switch wont work but the key will. It will come down about 2 or 3in by itself then i have to push down on it with my arm to get it to go the rest of the way down. Same on the way up it will go up about 2 or 3in then i have to help it back up. Could this be the motor? or somthing else?