[feller]

Upon further investigation, I have found the slider to be broken. And the frame simply looks to be an extension so the window will fit properly, but if it's broken im betting that's the problem. I did check the 3rd brake light and it appears to be dry with no signs or leakage (rust, wet dust and or dirt).
1st pic is the corner of the window/frame. The other 2 ar of the broken area