So I know I'm not the first to have power window issue, and I've read/tried the basic fixes, but I haven't see my specific issue (if I missed it, my bad.

In my '11 JKU Sport, my front passenger window will not lower only once the temperature is in the mid 70's or higher for a bit. The window will still raise, but just won't lower. Once the temperature drops again and the Jeep cools, everything works fine.

Anyone have any insight on this one??

 

Nothing has changed recently? You never take doors off or mess with the wiring harness? Just wondering if those can be eliminated from the checklist. The way I read that would be that you can roll window down on a nice sunny 80* day, but window wont roll up. If you went back out at night when temp dropped to 60*, it would roll right up like normal.....even if the jeep had not moved the whole day. IE....it really is just a temperature thing and the temp isn't some coincidence in your troubleshooting so far?

 

You're mostly correct, it's just the opposite. On a beautiful 80 degree day, I can't roll the 1 window down. If it's already down, it will roll up totally fine, just not down. If it's cold out, it works without any problems. As far as work done, I have actually recently bought this used as my next project, so I'm not positive as to what has been done, but wanted to check if anyone had experience with this before I started opening up wiring. All other windows work fine, and the 1 works fine as well...until it gets hot out.

 

That seems really strange. Can't imagine anything in there being temperature sensitive. We do have faulty switches from time to time, and the wiring harness at the door can be an issue from time to time. Outside of those 2 things you have the regulator in the door....but none of those should be affected by temps.

Since this is recently new to you.....I would start by closely inspecting the wiring harness at the plug to confirm there is no loose connection in a pin. I've had an issue with something similar in the past. Was positive all pins were making a good connection, but upon very close inspection, I could tell that as the door opened/closed, the wiring harness moved just enough and one of the pins was being pulled out just enough to cause an issue.

Troubleshooting the switch itself is usually easiest if you have a buddy with the same switch cluster that you can just swap in. That's probably getting a little harder to find on pre-'12 models.

Maybe someone else will chime in with an idea. Mechanical failure is understandable.....but the temperature thing is very odd.