Today I ordered some food in a drive thru and when I went to pull off, the window wouldn't come up. I pulled up on it and nothing. I decided to push down on it while trying to roll it down and it started working again and I was able to roll it up. It did it 2 more times today luckily I never rolled it completely down. Anyone know what the problem is!? Please help!

 

The only thing i can see is a tired regulator...

 

That's what I was leaning towards, but wasn't sure.