Had my 2004 Disco II for almost a year. I got it in the winter last year and the rear defrost worked over the entire rear windscreen. This year only the center section works. From research on the forums there is only one fuse so what else could it be? There are no cracks or holes in the rubber boot in the hinge area that might be exposing the wire to a short. Even if it was a short wouldn't that cause the whole thing not to function?

 

A small break our scratch to the grid can cause only part of your defrost to work. look at the thin brown horizontal lines for any broking or scratched away area. That would cause the defroster to only partially defrost the rear window. You can use a volt meter to test the grid to help find the bad spot and then buy a kit to repair it.

 

Yup. I'm in the same boat. Except, the middle grid is out on mine, it figures. I located the damage section (very slight break in the circuit) just haven't had time to make the repair. Honestly, I'm in no rush. I use mirrors to backup. Plus, I have 30% tint all around, tough to see at night anyway.