Figured it out. Pulled the amp and re-soldered the traces and components on the circuit board.
I'll try to post a pic of the bad solder joints. Electricity and electrical components are NOT German strong points!
The lines are leading to solder joints which were actually loose. You could wiggle them around in their sockets. Notice the darkened areas on the PCB. That is from poor connections leading to increased resistance/heat. Spent about an hour touching up ALL the solder joints, replaced the board and voila`! A/C working as it is supposed to now. Vents open and close, blower speed changes according to temperature readings, compressor cycles, etc.
NOT a job for the average week-ender. Requires a steady hand and a small soldering pencil. I used a 12 watt I have from my electronics repair days. Some of those traces are CLOSE together and it would be only too easy to create a bridge if you are not extremely careful.