Oh Great F150 Gurus....PLEASE help this Old Phart....I have a 2010 F150 Supercrew XLT. I have ran the complete gamut as to this issue and am ready to give up--yet I know that the knowledge base of this forum should be able to solve this!

The rear defroster and heated mirrors are not working. I have checked fuses, connections, relays, and switches.....and still nothing. After reading a couple thousand threads all over the net, it is my understanding that if the rear sliding window is not completely closed they will not work. Apparantly there is a contact point or points that when the window is closed completes the circuit. I am quite sure that this is the issue with my truck. I cannot figure out where these contact points are. Or if a simple adjustment to the slider will resolve this.

Could one of you fine members steer me to where to look for these contact points? might it be a matter of simply brushing/cleaning these contacts? Is there a way to adjust the slider portion to align these contact points?
I am losing my mind in regards to this.....PLEASE HELP!!!!

PS Yes I have tried holding the defrost button while operating the slider to a closed position and yet still have no defrost operation.