HVAC is DEAD! HELP Please!

[I'm Redline]

Background:
Every once in a while, the car will stall out when it's cold then be hard to start(motor turns over, press gas and it slowly runs up then runs fine) Last month this haoened and when the motor started, the entire HVAC just DIED. No switches, no lights, no fans, no anything.

What I have done:
I have checked all the fuses and fusable links(from what I can tell) and can find nothing electrical that causes this, HOWEVER, I am a total noob to this car(I know 66 Mustang with 351W, Datsun 310's with side draft carb and hot cam, and military flightline equipment) This mystifies me, and I know it is eaither a plug that has become diconnected, or a blown relay or fuse, but I cannot find it

Can anyone who has had this same issue tell me where to look, what to look for, and where in the vehicle to look for the parts that are the electrical for the HVAC. AS I said, I know it is a first line entry power issue for teh system, I am just at a loss to find the sucker. Nissan wants $98 to 'diagnose' and I think the guys at a local shop may not be close to qualified(but more than me) to troubleshoot this what I perceive to be a rather PITA small issue.

If you have assistance to offer, please feel free to email me from the email listed in my profile