I cannot comment 100% on your car. However my 99 has a rear defogger module, in the back part of the headliner. You have to lower the headliner a little to see the module. It is located right at the roof line, where the metal roof meets the rear glass. If it goes bad, of course the defogger will not work.
This module is also my antennea signal booster too, and that is what I do not know if your car has or not.
Also, if any or the main line on the rear window is broken, the defrogger will not work. Most of the time the lines are repairable. All except if like a small dog was pawling at the window and broke all the lines! I have seen this before!
