So my rear defog doesn't work. It was working last year, but apparently over the summer something decided to die in the circuit. I've checked the voltage at the glass and it reads 12V all around the grid. So I've determined that the grid itself is not faulty. My switch has a small light in it that does turn on when I push the button. So I don't think it's the switch but I haven't pulled it to check with the DMM. I can also hear the relay clicking from somewhere under the dash. The relay clicking also confirms my belief that the switch is good. I have checked every fuse in the fuse box and they're all good. Can anyone help me out? Something else I should check? Check differently? Thanks for your responses!

 

Does anyone possibly have the circuit for the defog? My Hanes manual doesn't have anything in it for the defog. Could the relay be bad?

 

Sounds like everything on the power side is working properly. The condition is likely caused by a faulty ground to the grid.

 

Thank you for the circuit! I've been looking for that all over. I'll make sure to print it.
Now you say a faulty ground, how would I get access to the ground point? I'm pretty sure there's a wire that runs into the pillar from the strut, but I don't know how to get inside there. Unless there's another point that the wire actually gets grounded?

 

The schematic states G998 as well as 'right rear d pillar'. I'd start there. Disconnect the ground then test continuity back to the grid. If there isn't continuity back to the grid, then there is a problem with the wiring and/or ground through the strut.

 

I'll make sure to try that. I'll be doing that after the storm though... Thanks for the help!

 

Looks like I may have found the problem. I checked the ground at the grid as Swartlkk said to and it checked out fine. I re-checked the power at the grid and it was also fine. I decided to check the resistance of the struts just for fun and make sure they had 0 ohms end to end. Well the driver side strut measured in at about 2.5 ohms, which is completely fine and normal. I then check the passenger side strut and found that it had 7.2K ohms across it. I found that abnormal.. I also measured the resistance of the grid which came out with a funny reading that jumped between 1.5 and 200 ohms (that could be the meter but it's still far less than 7.2K at the strut). I ran the math and it works out that if the strut was at 0 ohms the current would be (based on the varying reading i got) between 60mA and 8A. but factor in the strut and it goes way down to 1.6mA. I then measured the actual current going through the circuit and it was even less than the calculated value at 0.3mA! I think i know what the problem is alright. Now i just have to see if that strut is under some kind of warranty. Did I mention that these struts are less than 6 months old?! Thanks for your help!

Update: Replaced the strut and measured the current going through the circuit at 7 Amps. I'd say it's working just fine now!