Not sure about the contacts, but you should look further down in this forum at the thread called "rear window defroster or rear window exploding".
Apparently some of the 2010s have some sort of issue which can cause the defroster to short out or something similar. This causes the rear window to shatter. Apparently, the replacement windows being installed are of a different design.
Be careful with what you do with this, you may want to have a dealer look at it....
2015 F250 XLT FX4 Crew 6.2, Magnetic, 3.73 Locker, XLT Premium Pkg, Chrome Pkg, Sync, Flow-Through Console
SOLD: 2012 F150 XLT Screw 4x4 5.0, Ingot Silver, 3.55 Locker, Convenience Pkg, Chrome Pkg, Towing Pkg, Sync, Keyless Entry Keypad