I think my rear defrost is broken

Its winter and that means one thing- shitty weather. I will usually come out in the morning and scrape off ice from my front wind shield and remove snow from the base of the windows. Usually there isn't a thick layer of ice on the rear window, but it is clouded. Normally when the electric defroster works on other vehicles I've driven it will look like this.

But after 10 minutes of driving my rear window defroster hasn't done anything, it is still foggy. The defroster isn't effective an loosening small amounts of stuck on snow or clearing fog from the rear window. The outside temperatures range from 23 to 35 F (-3.8 to 1.7 deg Celsius).

I don't see any obvious breaks in the conductive material, is there some way to trouble shoot this issue or check that there is current reaching these wires?

 

I wonder if you could unplug it in the hatch and test the wires that supply it? It might be some screwing around getting the hatch skin off.

Or, maybe you can test for resistance at the fuse, or relay? There must be a way to troubleshoot this.

 

Does your defrost light come on??

 

Yes

 

Then i think i would preceed with what THEBASSGUY has stated. Relay,Fuse...then removing the rear hatch panel n check wiring n such in there...
Make sure the rear window is up the whole way also..if it isnt...it wont let current pass..

 

Had some dude rear end me and the hatch was replaced. Rear defogger didn't seem to work, so I went back and they checked the rear connection for voltage and reseated the connector. It mostly works now but seems weaker than I remember. I'm still thinking maybe there is a faulty wire in the harness that comes from the roof to the hatch. It's a known problem as these cars age.

 

There is a dent in my back tail gate. Hopefully that isn't the cause

 

A dent won't be an issue unless it knocked the connection loose. In which case, easy fix.

I think it's just a direct 12v to the glass panel. So not many things to go wrong.

 

Okay I checked the back tailgate today, there seemed to be nothing obviously wrong. Is there some way to probe the wires with a multimeter to check that there isn't a break in connection between the battery and the tailgate?

I forgot to check the fuses so I am going to do that right now and I'll update shortly what I find. Hopefully its a blown fuse

Update: Checked the fuse box (the one in the cabin), nothing seemed blown, but it was dark out so I'll do a full check tomorrow.