Have a 88 mercedes 300E and once the ignition is turned to position one the blower motor is always on even if 0 on the climate control is depressed. Have disconnected ACC and still runs only thing thats stops it is the external fuse. Are there any tests on the regulator i can do without removing it? Where is the connector or fuse?

Sounds like blower regulator , after you test it and find its bad ive got a normal functioning regulator out of my 94 e 320 should be the same part