The paint-on heating element has been damaged. Examine the bottom half for breaks or cuts in the heater element. You can purchase "paint on" repair material to make it work again, or you could purchase a new window if you're floating in money.
With a test light.
In my case the switch to the defogger was fried and had to be replaced. I would first determine where the problem is, then get a haynes manual and see how hard it might be to fix the problem yourself. If you can't do it then take it to the dealer.
I would go to a professional mechanic to have him/her fix it. Your issue could be an assortment of things; it could be the element in the rear window, wiring, or circuitry.
Check that the wire on the rear defroster is connected to the defroster. If broken off repair it.
I can't tell you the exact name of the part. I believe that if you take the back panel off inside next to the rear window where the defogger connects, you will find that the part is burnt. It will be on the passenger rear. Do not confuse it with the antenna. I went to a salvage yard and got one from a used Lesabre.
what is a window release?
It could be that the window motor has stopped working.
I have had the exact same problem with my 1990 wrangler, I found out that unless the handel that allows you to open and shut the rear window is not in the exact closed position and the window is closed tight in place, the wiper will not work but the washer will. Just for fun once I realized this I tried to turn the rear wiper on with the window open and it did not work until I shut it. Hope it works for you.
each window has it's own window regulator and window motor. so if one is working and one is not, you would have to take the door panel off and see if one or the other is working, or the window may just be off the window track
where is the rear window defroster relay located in a 2004 Toyota Four Runner, would this also control the rear wiper arm? Try something simple: just open and re-close the rear window. The window has a safety switch that keeps the wiper, washer and heater from working if the window is open. The window settles down (from opening and closing the hatch) over time the window settling triggers the switch. If you open and re-close the window it resets the switch and everything works again. My 2003 4 Runner does this over time. I just open it and re-close it to fix the problem.
the motor and the switch both work but the window will not move
A loose wire would cause the horn to stop working on your Dodge Avenger 2.4L engine.