I've never seen any indication that they fixed the risk of the window exploding, so replacing the window with a defrost-capable unit and plugging it in will likely restore the risk. You can install a defrost-capable window but not plug it in, or you can just install a window without defrost.

My truck is supposed to have defrost and a power sliding window, but somewhere along the line it got replaced with a blank normal window, no defrost, no slider.

 

Well, I checked... there is no continuity across the glass (I expected this), and I get 0 volts on both wires at the gray connector after I push the rear defrost button. I'm talking about the gray connector on the passenger side, on the rear wall of the cab, just below the glass. Based on where the wires go, and where the ground wire goes on the driver side, I was thinking this was the window wiring harness. Not sure where the yellow and black wires go though. I would have expected only one wire for the window heater. Maybe the other wire goes to the slide motor. In any case, after pushing the rear defrost button with the key in the "on" position (engine not running), I got 0 volts on both wires -- that's 0 volts measured against chassis ground.

 

thats the same spot but cant remember if it works key forward or have to be engine on - wouldnt hurt to try. I believe the 2 wires are there completing the circuit after power has passed through the defrost system and thats what sets the light in the button. If you jump the wires to make the dash button light work thats where you do it coming out of that connector.

 

Yeah, I'll try again with the engine running - won't hurt to check that.

 

it may just be me, but I never look out the rear window anyway, it could be painted black and wouldn't make any difference. I have side mirrors, and if backing up, I have the camera. It's kind of hard to see over the bed and rear seats anyway, massive blind spots, I don't know why they bothered installing a mirror on the windshield in the first place.

 

I have a 2014 bought it used and rear defrost also doesn't work. Up on troubleshooting. closing and opening the rear slider a few times worked. There are contacts in sliders that are no longer making contact to complete the heating circuit. Pretty ****ty design.

One day whole inside was foggy and it didn't take long to clear up the rear fog. I don't think it's even a necessary feature at all.

I don't know why Ford did it that way, The Slide should be on its heating circuit or just choose not to have it on the slider at all. Or just put a nice weather strip on the slider and open and close it to wipe the fog off.

For now, I just bypassed it but shorted the heater wire so, rear-view mirror heaters work. Which is great to have up here in the NorthEast.

 

Somewhere to hang my fuzzy Rubik's cube dice.