DDK - Die Deutschen Klassiker

Afternoon all
Hoping this is an easy one, save me jacking the car up. The small heater lever (just behind the gear stick) has a broken or disconnected cable, what does this lever control? I assume it is just to let air into the cabin heater system and is not there to allow the engine to cool? I have no heating system in the car as the exhaust is an after market one, I just didn't want to run the car and overheat the engine if the cable controlled something else.
Any help greatly appreciated.
Jon.

It has nothing to do with cooling the engine.

Nice one, cheers.

It controls the heater boost fan which pushes hot air through the heat exchangers into the cabin. If it's connected,and you turn the ignition on, you will hear the fan motor start if you pull the lever towards the back of the car.