Smooth cruising. That's how you would describe your driving experience if your car's air conditioning (A/C) system was working perfectly. If it feels like the A/C system's losing its breath, however, something must be wrong with the blower fan.It's probably the blower motor resistor breaking down. The logic behind the blower fan is pretty much like any simple circuit - there's a source, a load and a switch. In the fan's case, the battery or alternator is the electrical source and the blower motor is the load.Its switch, though, is a bit complicated. The blower motor resistor acts as a three-point switch, increasing or reducing the amount of electricity passing through to control the fan's speed. If this resistor breaks down, the fan may run only at a single speed, or worse, it may refuse to run at all.To fully enjoy the benefits of your car's A/C system, keep the blower's motor resistor in good shape. In case you need a motor resistor replacement, you can take your pick from Carparts's catalogs.
• Helps the blower fan provide air for the A/C system
• Allows the fan to spin at different speeds
• Available for various makes and models