testing heater system with engine off?
 

I would like to test all components of the heater system. I do have the Bentleys manual explaining what is where to do what.

Question 1: Knowing that there are quite some basic but smart sensors in the system, is it possible to test it with the engine off (but warmed up)?

Question 2: how/where is the speed of the footwear blowers controlled?

What year and options of 911 do you have.

On my 85 there are no sensors anywhere in the heating system. Super simple to test.

it's a 86 targa with automatic temp control. There is a heat switch on the heat exchanger to ground the blower motor(s) as soon as engine is warmed up, and a temperature sensor in the dash.