Blackbirdsc

My 2006 ford f150 fx4 fan seems to only blow at one speed. When I change the fan speed with the switch you can hear the fan change speed bit no change out of the vents. Any ideas? The air leaving the vents never changing speeds even though I can hear the fan change speeds. I thought that if the resistor is bad it would blow at a high speed. The air comeing out of the vents couldn't blow out a little match.

nrivera04

What speed does it blow at? I'd suggest the blower resistor behind the glove box. Less than $20 pickup at a chain store and 10 mins to change.