1978 280z. Rear window will not de-fog. I have changed out the switch and panel light and have 12 volts to the connections at the window. Any hints on what to do to make it de-fog?? Thanks for your interest.

Since you have power to the defogger connections, it would seem that there is a continuity interruption in the path of the defogger. If there is a scratch or crack there could be your issue. I think the FSM has a procedure for fixing that (at least I recall one in my '72 FSM).

I tried to fix mine but ended up replacing the window about ten years ago. We talked about defoggers/rear windows etc. here:

http://www.classiczcars.com/forums/showthread.php?t=28305

If the defroster grid is damaged, you may be able to repair it. See m post at the end of the above-mentioned thread.