I am trying to sort out issues with my just acquired 1983 300D, one at a time. The problem I am having is that radiator fan keeps always running, even when the car is cold, even without running engine. The engine runs cold, does not go more than 50 degree Celsius. Besides it appears that heater core is leaking (mist on the passenger side windshield and a smell of coolant). Not sure if this is somehow associated with radiator fan, but from my past experience, the constantly running fan was caused by bad thermostat sensor. Please advise your opinion. Thanks!