'84 5kS HVAC Question

["Buchholz, Steven" <Steven.Buchholz@kla-tencor.com>]

My brother-in-law has been wanting me to look at his car ('84 5kS with the
late-84 style HVAC system) as the AC Head was completely blank and he was
getting no heat.  First thing was to check the fuse (S13 if memory serves).
The fuse is good and I see battery voltage on the Blk/Blu wire coming from
the fuse box.  Next I go to the control head ... it isn't getting the 8v
signal it is expecting from the programmer.  Next, the programmer ... first
look shows that it is not receiving battery voltage from the blk/blu wire!  

We ran out of time last night, so I pulled the bowden cable from the
programmer and stuck it in the glove box, so now he can get warm air into
the car if he wants it (through the defrost vents and there's no blower).
I'll be digging into the wiring from the fusebox to the programmer next
week, but I thought I'd post my quandry to see if there were any BTDTs out
there.  All suggestions graciously accepted!

TIA!
Steve Buchholz
San Jose, CA (USA)