2000 Blazer still blowing hot then cool air

Originally posted back in October 2011
Auto facts: 2000 Blazer
Mileage: 240,000 Engine: V6, 4.3L Transmission: Automatic, Drivetrain: 4WD, Auto climate control
October 2011 had my AC compressor assembly replaced, renewed accumulator/receiver drier, orifice tube, recharge, etc. The AC was cooling well below par very quickly after the repairs.
APRIL 2012: ACTIONS TAKEN BY MY LOCAL/BACKYARD MECHANIC:
Dropped glove box and dash bezels…
Replace blend door actuator motor (used) - no change(original reinstalled)
Try a used Auto temp control panel (used) - no change(original reinstalled)
Locate Heater control module and unplug harnesses,no change
Locate Body control module and unplug harnesses,no change
Unplug temp sensors in duct work,no change
Unplug A/C cooling switch,no change
Got through a mild Wisconsin winter with good heat, now need A/C
June 2012: MORE ACTIONS BY MY LOCAL MECHANIC:Recharged the A/C system to get the clutch to engage (still leaking from last fall) Did the RDO Reset with dials set to AUTO,no change.
it’s still blowing HOT and not so hot. Possible the used parts were bad too? Have read that the gear inside the blend door actuators fail. A/C lines never cooled down. If I remove the “service here” cutout under the hood by the firewall can I block the door in position to allow only A/C?