STARTED MY VEHICLE ON A COLD MORNING TURNED ON THE WINDOW DEFROST AND REAR DEFROST. CAME BACK TO IT A FEW MINUTES LATER AND THE BACK WINDOW WAS SMOKING AND THE GASKET HAD CAUGHT ON FIRE. IT SHATTERED THE WINDOW AND BURNT AND MELTED THE GASKET. THIS SEEMS TO BE A BIG PROBLEM WITH THE F150 WITH REAR DEFROST AND POWER SLIDING WINDOW IT EITHER BREAKS THE WINDOW OR CATCHES FIRE MINE DID NOT EVEN BLOW THE FUSE. HAVE SEEN MANY CASES OF THIS THRU F150 FORUMS AND FORD HAS NOT COME UP WITH A SOLUTION. IT IS ALSO A VERY EXPENSIVE FIX . MY VEHICLE WAS STATIONARY IN MY DRIVEWAY HAD I NOT CAUGHT IT IN TIME THIS WOULD HAVE DESTROYED MY TRUCK AND CAUGHT MY HOUSE ON FIRE TOO