Mercedes-Benz S420 Repair and Maintenance
A guide to problems, costs, maintenance and repair for your Mercedes-Benz S420
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Mercedes-Benz S420 ProblemsTransmission Oil Seals May Leak on High Mileage Vehicles
High mileage vehicles may develop a leak from one or more of the transmission oil seals.
Other than a defective motor, a bad switch or blower motor resistor assembly can cause an inoperative heater blower motor.
A refrigerant leak may develop from one or more of the following AC components: AC compressor, hose manifold for the compressor, or the evaporator core. The loss of refrigerant can cause poor AC performance. Our technicians tell us that proper leak diagnoses should be performed in order to determine the cause of any refrigerant loss.
Mercedes-Benz S420 QuestionsThe heat works great but blower continues to run when the car is turned off? (1 answer)
Replaced the resister. Blower continues to run w.hen car is off. Have to unplug resister to shut off. Heat, air conditioning, blower and controls all work great, except for blower not shutting off when car is turned off.
When I apply the gas it decreases everytime.