When a blower resistor fails, the highest fan speed usually is the only one that still works because it essentially bypasses the resistor and receives the maximum amount of voltage. When the resistor is working, it reduces the amount of voltage going to the lower fan speeds, so the fan runs slower.Jan 17, 2016
How do I know if my blower motor resistor is bad?
- Only One Speed From Blower Motor. One of the most common symptoms of trouble with the blower motor resistor is when the fan gets stuck in one setting. ...
- Various Airflow Settings Not Working. ...
- No Air Coming From Vents.
Why is my AC barely blowing air?
Problems like a fan clogged with dirt, a dead motor, a loose fan belt or a stuck wheel can all cause your blower to not work properly. These problems can keep the blower fan from blowing enough air out of your vents to keep you cool. Your evaporator coil needs air to blow over it to complete your AC's cooling process.Sep 14, 2015
Why does my AC only work on hi?
If your air conditioner works on high, it is a very specific issue. It can mean that there is a problem with the blower motor, the control board, or the thermostat. However, we still do a full diagnostic check-up to ensure that all of the switches, wiring, and fuses could not be causing the same issue.
What causes a blower motor to only work on high?
Most car manufacturers use a series of resistors to make the heater blower motor run at different speeds. And when one or more of these resistors burn out, you're usually left with only one heater blower motor speed—high. ... Remove the screws, and swap out the resistor module.
Why does my blower fan only work on high?
Most car manufacturers use a series of resistors to make the heater blower motor run at different speeds. And when one or more of these resistors burn out, you're usually left with only one heater blower motor speed—high. ... Remove the screws, and swap out the resistor module.
Why is my AC not blowing a lot of air?
Problems like a fan clogged with dirt, a dead motor, a loose fan belt or a stuck wheel can all cause your blower to not work properly. These problems can keep the blower fan from blowing enough air out of your vents to keep you cool. Your evaporator coil needs air to blow over it to complete your AC's cooling process.Sep 14, 2015
Why is my AC only blowing on high?
When a resistor fails, the fan will often run only at higher speeds or the highest speed, no matter what fan speed is selected. ... If little air is coming through the vents (hot or cold), then it could be because the blower motor for the fan or a switch or resistor that controls fan speed isn't working.