Blower Motor Resistor

HOW TO DETECT THE PASSENGER COMPARTMENT FAN SPEED REGULATOR FAILURE

The fan speed regulator should be tested as follows. You have to dismantle the part, and connect the wires going to it directly with each other, using a jumper. If, after doing this, the fan turns on, the tested component is defective. Besides, installing a known good part in the place of the tested regulator will help to identify the failure of the latter.

If you have a multimeter, you can check the component serviceability by measuring resistance. The obtained results should be compared to nominal values that are usually specified in the car technical documents.