Blower Motor Fan Stuck on HIGH

[50Dutchman]

I have a 2010 Ford Explorer Eddie Bauer with automatic dual climate controls. A couple of weeks ago when I started the vehicle the Blower was on High and would only shut off when I turned the vehicle off. Other characteristics below:

1) Digital fan speed will go up and down, but does nothing to the blower speed.
2) On/off switch only changes it to auto...no effect on speed of blower.
3) Fan location dials work, i.e., floor, defrost, etc.
4) Temperature controls work fine.
5) Can switch between A/C and heat just fine.
6) Blower stuck on HIGH speed.
7) On only when you start the vehicle and off when you shut the vehicle off.

Can anyone help??

 

[Turdle]

Hmm, Sounds like the ac max blower relay has stuck closed. Try turning on the key, then smack the relay box with a screwdriver handle. See if the blower kicks off after that.

 

[50Dutchman]

Where exactly is the relay box located?

 

[Scorpion8]

You have a bad blower motor resistor. It is a variable resistor right where the electrical cord goes into the blower motor. Controls fan speed by dropping different voltages across the fan power.

 

[50Dutchman]

Thank you for all your help. It was indeed the Blower Motor Resistor. It was fried!! Replaced and is working great. Thanks for your suggestions.