Where is the blower motor resistor regulator located. My 1986 560Sel Mercedes.

3 wires on plug under dash that go to the motor, for it to work through its stages of climate control you must have a constant 12 volts to the GREEN top wire(NOT A GROUND),if there is no 12v when you activate blower switch then link via fuseable resistor or 10amp fuse holder to ignition live, do not forget to remove old wire that is already there