The blower motor resistor in your vehicle regulates the electrical current flowing to your vehicle's blower motor. This regulation of current causes the fan to spin faster or slower, resulting in more or less air flowing from the vents. If the blower motor resistor fails, it can overheat and burn the wiring harness that connects to it. Fortunately, you can purchase a replacement wiring harness from either the dealership or a salvage yard. The replacement process is a relatively easy task.
Remove about 1/2-inch of wire cover from the ends of the wires on the replacement wiring harness, using the wire tool. Insert the exposed wire ends each into one side of a butt-style connector and crimp the connector using the wire tool.
Remove the wiring harness from your vehicle's blower motor resistor. The exact location of the resistor varies between vehicles, so use your repair manual to locate it.
Cut the tape from the bundle of wires connected to the harness, using the utility knife. Peel the tape from the wires. Notice that the wires are color coded and match the colors on the replacement harness.
Cut the old harness's wires, roughly the same length as the wires connected to the replacement harness. Remove approximately 1/2-inch of the covering from the wires that the old resistor was connected to.
Connect the butt-style connectors on the ends of the new harness's wires to the matching-colored wires in the vehicle. Crimp each butt-style connector to the wires in the vehicle with the wire tool and wrap them in electrical tape.
Wrap the entire bundle of wires with electrical tape, just as they were prior to cutting off the tape.
Plug the harness back into the blower motor resistor.
