Posted on 1/1/2021
You expect your heater/air conditioner to work like it should. You have a control for temperature and one for fan speed. You even have a control for what vents the air comes out of. Don't be surprised one day if your blower fan develops a mind of its own and starts going crazy. Most of the time, you may find that it starts blowing at full speed, and nothing you do to try to control it does any good. This is what may be happening. Your blower motor has an electronic component called a resistor. It does what its name says; it offers resistance. When you want the fan to run more slowly, you turn the fan speed down. That resistor accomplishes that by turning its resistance up. When the resistor fails, the power has nothing to slow it and the fan speeds up. It's a small part and can fail due to age or corrosion. It's usually not an expensive part, either, but it's often found in a location that's not that easy for the technic ... read more