testing heater system with engine off?

[alexandervdr]

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?

[GH85Carrera]

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.

[alexandervdr]

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.