Asked in
Mercedes-Benz 300-Series
Timing Belts and Chains
Ford Expedition XLT
Heating Ventilating and Air Conditioning

How can I tell if the heating-cooling controller is bad on a 1990 300E?

Answer

User Avatar
Wiki User
June 06, 2009 10:20PM

Without borrowing a known-to-be-functional unit, you would have to make sure your air conditioner is fully charged and that your Mono valve is working properly.