1981 Mercedes Benz 300TD Base 5 Cyl 3.0L
only high heat; cannot regulate the temperature
No matter what temperature I put when I turn on the blowers I only get high heat. The fan works and can be changed. When I turn off the fan I don't get any heat at all
Did you already check your heater control valve and its cable or vacuum hose? Also a defective switch can cause it.