Driver window does not always work

I need to take my jeep threw inspection and Icantget the window working right. The drivers side window will work sometimes. It will usually roll down a little bit and then stop it gets stuck down allthetime and the only way to get it back up is to beat on the door right where the window switches are. The window works the best in the summer when it is real dry out and it never works when there is moisture in the air(it never works in the rain). I have had the door apart and I could not find anything wrong with any of the wires; because it seems like a short or a lose connection but I could not find one anywhere. Also every other window works fine just except for the drivers door window. I was thinking this must be the switch but I don't want to spend eighty dollars on a non refundable part if that's not the problem. As i said if the window gets stuck and u bang the door near the switch I can get the window to work long enough to get it up. I never put the window all the way down I usually only crack it so ican smoke. Any help would be highly appreciated because ican not even get a t tag without my window going down and I have to drive my jeep rfkegardless cause I have toget to work. So the sooneri get it fixed and tagged the better. Any ideas on suggestions are valued I amleaning toward that it is the switch but I am not sure thank you JOSH

I have had this post up for about a week and I appreciate all the attention it has gotten and all the information you guys have given me it has helped out alot. Of course I am not referring to this thread obviously cause no one responded. I am referring to all the information I have got by searching; I all ways search before I make a post cause nine times out of ten sOmebody all ready posted about it and I can find what I need; I rarely post and when I post it is because I can't find what I need when I searched. I have narrowed it down to two things with the research I dI'd and after looking at the door before it has to be most likely the switch or there's a short. I all ready assumed it was the switch now I am about positive. The only information I could find about a switch is when they go bad they just stop working they dont go gradually bad. Last to
Time I took the door apart I found nothing wrong with the wireing. I am going to take the door apart today and take a look at it. I am going to use jumper to bypass the switch and send power directly to the motor that way I will be able to l if it's the switch or what. Also the funny thing is my passenger seat acts the same way with the motor that moves it forwards and back. You can move the seat all the way up but by the time the seat gets near all the way up u can gradually hear the motor wind down(it sounds like when a electric motor is hooked up to a battery; and as the battery dies the motor gradually slows down
). Then the seat will still move up an down but it will move forward or backwards. Then I wait fifteen twenty minutes and the seat works fine; then I will move the seat all the way back and by the time it gets back it dies again. The window does the same thing;except when it stops moving u have to either wait a very long time like a couple days or bang on the door to get it working . If anybody has any experience with something similar to this or have any idea what it could be let me know please. I think it's the switch but my buddy who is a mechanic thinks its the motor. I have seven days to get this fixed. I am going to go take it apart now; when Im done I will post what I found out. Any help is highly appreciated

Apologies for the slow response; many of us aren't on here as much as we used to be. Sounds like you are on the right track....verify that motor works, check connections to switches, and replace switch if everything is in good shape. While you're at it, make sure to inspect the wiring closely; a rubbed spot could cause a short which would make the intermittent problem happen.