A problem we have had for quite some time now is the fan for the heater/air conditioner only works on high. None of the lower fan settings work except for the highest setting.
Our other problem as of currently (last 6 months) may be related to the previous problem. The engine coolant temperature takes a long time to get up to normal temps which is around 170-190. Only if we leave the heater fan off will it come up to normal temps but only if we do highway driving.
We also have a check engine light on currently.

 

Sounding like your blower motor is acting up, could be the motor or just the little resistor on the blower motor has gone bad.

Also sounds like you need a new thermostat on the engine.

Check/Search the "How To" section for how to's on fixing both yourself.

Have the check engine light read at one of the auto parts stores that does it Free and find out what it is, could be a warning on the thermostat problem. Or something else.

How to save $350.00 + (Thermostat Replacement 2.4L)
https://www.chevyhhr.net/forums/how-tutorial-library-21/how-save-%24350-00-thermostat-replacement-2-4l-p0128-24493/

Heres a quick "blower motor" search I did for you, start reading a few, as you may also need to fix a water leak getting to your motor, a quick patch.
https://www.chevyhhr.net/forums/sear...archid=2135256

Gonna all depend on what your actual problems are.

 

X2 what A&P posted above.^^

The blower description sure does point to a bad resistor. Also since it is a 2006, you should check for that known water leak on the passenger side.