2010 Explorer XLT AC Blower speeds 1-3 not working high works

[cbexplore]

Got in my truck for lunch today and the AC blower isnt working on speeds 1-3 but high works?
What would cause this? thx!

 

[hibbbbbs]

Blower Motor Resistor - super easy to replace. It should be behind your glove box. The part is about $20.

About halfway down someone posted a brief how-to: 07 Explorer blower motor resistor?

 

[cbexplore]

Blower Motor Resistor - super easy to replace. It should be behind your glove box. The part is about $20.

About halfway down someone posted a brief how-to: 07 Explorer blower motor resistor?

Thanks hibbbbbs