Rear Defogger (2013 Legacy Premium 2.5i)

Good afternoon.

I am having trouble with the defogger (rear window).

I read that it might be the wiring contacts (they may be loose). However, I do not know where the contacts are located - is it within the back pillars, is it in the boot, is it behind the seats where the rear speakers sit?

Thanks.

Typically those contacts are on the side edge of the window near the C pillar. I had to re-soldier them on my old Monte Carlo. If you get in the back seat facing the rear and put your head against the glass look right and left and you should find them somewhere.

Additionally if your side rear view mirrors also have the defogger they might be tied in the same circuit and if one of those is out it could also cause the rear to go out.

Typically those contacts are on the side edge of the window near the C pillar. I had to re-soldier them on my old Monte Carlo. If you get in the back seat facing the rear and put your head against the glass look right and left and you should find them somewhere.

 

Additionally if your side rear view mirrors also have the defogger they might be tied in the same circuit and if one of those is out it could also cause the rear to go out.

Thank you, I will look.

My side rear view mirror do have defogging and those work flawlessly. It is only the back window that is basically not working at all.

I had to re-soldier them on my old Monte Carlo.

What year? I re-soldered the contacts on my mom's old '96 Monte, wonder if that was a common thing...

From what I'm seeing, the power running to the rear windshield deicer is what energizes the coil on the mirror heater relay, so if the heated mirrors work, you should at least have power coming out of the fuse block. There should be a 2-pin connector back there somewhere (maybe in the trunk at the base of the windshield?), and if you poke at the car-side connector, you should have 12V on one side and some non-zero resistance value on the other side. No power is obviously bad, very low resistance is a short upstream of the heating element, and open circuit is also bad.

Look closely at the whole grid too. My sister once borrowed my old ‘97 Outback Wagon back in the day and crammed the back full of stuff. When she slammed the hatch shut, something scraped against the defogger grid. It didn’t work after that. The whole things a circuit made from resistive paint that heats up when you run a current through it. If it gets scratched, it’s just like when you scratch the traces on a circuit board and sever them. I was able to find the breaks due to them being a slightly lighter color than the rest of the grid, but you can find them with a multimeter too. If you turn the defogger on and set your meter to read voltage, you can measure the voltage between two parts a few inches apart. The voltage should be fairly small. If it’s large, there’s a break someplace in between the probes. They make a conductive paint you can use to bridge any gaps to make the circuit contiguous again.

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