Thuso

The heater comes on when the car starts in the cold. It runs for 3-5 minutes and turns off. Controls indicate fan speed and temp, but the fan motor stops. When the engine warms up the heater can be restarted by turning off the engine and restarting the car.

tcora

Probably a good question to ask in the 981 forum

https://rennlist.com/forums/981-forum-264/