I scoured the forums to see if I could find this issue already but didn't get anywhere.

Have an '05 Grand Caravan that rear defrost no longer works. The heated mirrors still work, but the back window stays frosty.

When it was working I used to notice the engine work a little harder at idle with the additional draw, doesn't do that anymore.

My question is... is there a separate fuse that sends power to this or is there a common spot in the wiring that is at fault?

 

The FCM sets a ground to the defogger relay coil when you switch them on. The relay supplies power to both the mirrors and the rear defog. All that is working. 40 amp fuse #13 in the fuse box controls power just to the rear defog. Check that.

 

Thanks very much, I'll check that out.