Heating not working

[Lovemyev]

From reviewing other post I suspect might well have been the "resistor", that is the unit that heats the air in the A/C failing. The fan is blowing air into the passenger compartment but it is only at the ambient temperature.

I was of the opinion that the "resistor pack" only controls the turning "speed" of the 12 volt heater fan motor itself ?.
Without the resistor in-line, the heater fan motor would be left producing one single max speed.
Installing a resistor, allows the fan speed to be reduced in speed in incremental steps.
This is very common way of stepping down the fan speed on many cars, not just EV's.
Normally when these resistors fail, they can either fail completely and stop all together, or the lower speeds fail, and you are just left with the single MAX speed only.
The "heat" side of the unit, is similar in the way it works as the old type of electric fire for the home.
The cabin heater in a an EV is a greedy beast ( when it comes to consuming energy ) and given is high consumption of energy, then it needs to be supplied by the traction battery and not the 12 volt battery.
If ALL of your blower speeds are working correctly and not cutting out, then I don't think the resistor is your problem here unfortunately, but I could be wrong.