What a great forum thanks to you! I think our car has had all the classic problems in the 12 years, 200km we have had it. Everything from the oil pump bolt (bent two valves) to the fuel filler door hinge has failed. All of the advice to track these down and repair them has been found by just searching the current posts or the archives....until this week. Too bad I didn't read about the oil pump bolt before it broke. This is my first post to solve any problems.
I have narrowed the problem down to the blend flapper that diverts the airflow through the heater core. Everything else seems to be fine (vacuum tracked and present, water valve opens/closes). If I manually open the blend flap I can get full heat but the heater knob wont move it (fancy feedback electric positioner for the electric gear driven flap positioner). I took apart the HVAC controls and didn't notice anything on the board (confirmed variable resistance on the pot at the temp control knob) and confirmed that the electric blend flapper motor actually works (power on the contacts at the motor got it to move) but I'm at a loss. Clearly I'm not getting any power to the flapper motor but the board inside might have me beat.
Anyone got any other ideas, things to try or should I give up and order a brand new HVAC control for it so I can have my hot wife happy again?