I acquired this 86 300ZXT in July and have been gradually working out electrical bugs (you can read my other posts). Most recent was the climate control. When switched to ACC or ON the display backlight would come on but no images on display and none of the buttons worked except for the defrost override. I checked all the AC & blower relays and fuses and they were all good. Also noticed that the clock backlight was working but the clock display was not coming on. I pulled the unit, applied a 12v source to the clock (thought I play with that rather than the more complicated climate control box) and the clock powered on properly. Consulted the diagnostic protocol as described in the FSM and found that one of the 3 pins to the Climate control unit that was supposed to be getting 12v power was not. Traced the wire to the Hazard light fuse which turned out to be blown. Replaced fuse. Climate control powers up and and display functions. Now just need to see if it is controlling the vacuum servos correctly.

 

Glad you got it sorted. I had a 928 which are notorious for electrical gremlins. Often I'd figure one thing out only to see another stop working.