Hello All,
My blower for the HVAC system only works on two settings out of the four. Speeds 1, 2 are working not speeds 3,4
- I have replaced the blower resistor still doing the same.
- Visually checked the fuses for the blower fan, the AC.
- I have pulled the blower out. I did not find any grinding or rough areas when spinning the motor.
- Blower turns on at lower speeds.
How do I go about diagnosing some of the other possible causes?
If your just throwing parts at it, I’d say throw a speed selector switch at it next.
Why would you say I need a new speed selector switch?
“Why would you say I need a new speed selector switch?”
Heh, heh…I’ll refrain from answering that. Instead, I’ll suggest getting a circuit diagram and do an actual diagnosis.
Because that and the resister control the fan speed. Since you already found out the resister that wasn’t the cure the fan speed switch is the other obvious choice.
Now that will take all the fun and mystery out of it.
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You can test voltages at speed 1 and 2, I would suspect the blower motor. Follow the trail and if it ends fine at the blower motor you have your answer.