There is a better chance of you having a weak window motor. Take the door panel off and bang on the window motor with your hand. If you can't or don't know how to rake it off bang next to the speaker with your hand. While you are banging it continuously try to lower the window. That's a common trick. I have to do it with my drivers window periodically.
1994 Mustang GT
Bought for $2200,Had 97K miles,New fuel tank,New driver front hub,New pass ball joint,New alt, New battery,New fog lights,New plastic bezel shifter,Fixed check engine light,New tires,Coolant flush,Magnaflow exhaust. Its starting to come together towards stock THEN I will make it go FAST!