I am a bit perplexed with my heater box. I only have heat from the right side, and intermittent cold to sightly warm air on the left. I did have a code, and I did fix the left blend door arm with an aluminum replacement part. All stepping motors are working. I did remove the motors and moved the flaps manually (they moved freely), with no change in heat on the left side. I did the auto re-calibrate when I was done. I took the left, elbow vent off to gain better view of the parts. The blend door shaft is intact, and moves freely by hand and when the stepping motor is engaged. Is there a blend flap that I am missing? I bought the car used,(2001 Saab 9-5 SW 2.3L) and it was like this from the beginning. any help would be greatly appreciated.