pak52

Cleaning the switch turned out to be fairly simple. The bulb case pops off the side of the relay revealing the guts. Cleaned with contact cleaner and a small brush. Works like new.

Looks like the part is no longer available. Anyone had any luck finding a source?

No, not directly, however, indirectly it looks open, because I was able to jumper around it and make the circuit work.

I found the fuse. It's ok. It looks like the switch is bad. I noticed that when I jumper around it, a relay clicks on. Funny - the schematic doesn't show a relay in line. Another one of those oddities.

Thanks to all for your help. Now that I have the schem, can anyone tell me where the 20A fuse is located that's shown in line with the rear defroster? Also, just in case, where is the Acc Relay mounted? fyi- I bought this '73 240Z new when I was in the service. Had crankshaft problems in '76 - swapped in a chevy 327. Drove it for 4 or 5 more years. Then it sat. I thought I was through fooling with it. Then my son grew up and decided he wanted to rebuild it (with my help), for his car. So... as you know, there is always something going wrong - it's pretty old after all.

I'll be darned if I can find the rear defroster circuit on that diagram... Does any one see it?

No, I don't have 12v at the grid. I looked at the schem you posted a link to - couldn't find the defroster circuit ??? I moved recently and can't find my SM.

I'm trying to trouble shoot - anyone have a circuit diagram?