1990 Mercedes-Benz 300SEL Repair and Maintenance
A guide to problems, costs, maintenance and repair for your 1990 Mercedes-Benz 300SEL
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1990 Mercedes-Benz 300SEL ProblemsBad Switch/Blower Motor Resistor Assembly May Cause Inoperative Heater Blower Motor
Other than a defective motor, a bad switch or blower motor resistor assembly can cause an inoperative heater blower motor.
A rough running motor or lack of power can be caused by a failed distributor cap or rotor, ignition wires (or their resistors), or valve cover gasket leaks. If the valve cover gasket leaks, oil can pool where the ignition wire resistor connects to the spark plug. The resistor can fail and the spark plug may not fire because of a short circuit through the oil.
The fuel pump and/or fuel pump relay can fail, causing the car to crank over but not start. Proper diagnoses will be necessary to confirm if the pump or relay is at fault.
1990 Mercedes-Benz 300SEL QuestionsNo owners manual ... Does this car have a3 or 4 speed transmission? (1 answer)
What transmission is in this car 3 speed or 4 speed?
And if so is it better to buy a brand new one or is getting a rebuilt one just as good thanks and I look forward to my answer