GMC Repair: Blower, 2007 gmc sierra, valve actuator

Question
I have a 2007 GMC Sierra.  The fan motor has stopped working on anything but the vent.  It blows fine at all speeds but it will only come out of the vent.  This just started so I'm not sure what to do.

Answer
Hi
Is it a dual system? Either way It is probabally the mode valve actuator. If you could take it to a good repair shop and have the HVAC control module scanned, it will again, probabally have trouble codes stored for that particular actuator.
The mode actuator is located (for the left side) on the left (drivers side) of the HVAC case in the area above the gas pedal.
For the right side,  it is on the opposite side (passenger side) in the same general vacinity. I would have it properly diagnosed first, it MAY be a wire, connector or terminal issue also. When a fault is detected, the system "defaults" to certian positions. It MAY start working properly again, but I would have it checked to save time and $$$$$$$$.
Thanks and hope it helps.