AC + Heat Problem Diagnosis

[my12by60]

On my new to me 2000 I have cold AC but no heat. My vent selection switches are set to dash vents, but none of the other options will work when selected. I ran the self diagnostic in the FSM and received the fault codes that I expected to receive after studying the diagram of system airflow in the FSM. In step 2, I received error codes 26 (air mix door motor) and 27 (bi-level door motor). In step 3, which is for the position of various air mix and air discharge doors, all of the codes (31 through 37) were blinking, indicating that all of the doors are in the wrong positions.

So the various doors are not moving to the positions that the system is telling them to move to.

Has anybody else had similar system problems and similar trouble codes?

Does it sound like either or both of the air mix motor or bi-level door motor are the problem?

Somebody told me that these motors are no longer available. Is that true?

Any ideas are appreciated.

The current setup is not a disaster because we are in Phoenix and I hardly ever use heat anyway. And the AC does work well and blows very cold through the dash vents, which is where you want AC to blow. Just thought I would explore a fix in case it was something fairly simple and inexpensive.