[jrehm]

My blower motor will sometimes not run automatically unless I press the Defrost button and then put it back to whatever mode I want. Pressing the Defrost button will always bring it to life and then it will work automatically in any other mode.

The other thing I noticed is that pressing the high or low speed button will also not work until I cycle the system with the defrost button.

 

[Stevenpfaff]

You may have worn brushes on the motor which causes the motor to only be able to start up at full power but once the motor is running the brushes will work. There has been quite a bit of talk about replacing brushes, so do a search on that. I would wait for another opinion before you spend any money though, someone else may know more about this than me.

 

[jrehm]

I will probably check this anyway when I take the blower apart because it has some squeeks (sounds like a cricket orgy [)]) now and then when in high speed mode that can drive you nuts.