I had a similar problem in a Pontiac Sunfire. The guy at the dealership said it's a common problem with the switches they use for fan control in Chevy/Pontiac vehicles. It's about a $10 part.
Could be a faulty fan motor and/or switch.
blower motor resistor is bad
AnswerI think it is the switch or the wires. Actually it would most likely be the resistor motor is shot, if the blower motor only blow on high there is no resistance thus it will only work on high.
Switch problem? Cables disconnected?
No. It can be a blown fuse, bad fan motor switch, bad fan motor, bad fan motor resistor pack, or a loose or disconnected wire.
On most vehicles, it only runs when the temperature is high enough or the ac requires it.On most vehicles, it only runs when the temperature is high enough or the ac requires it.
Had one that the fan motor was going bad Was burning out resistors with high draw
blower motor resistor
the blower motor resistor is bad or the connector going to it
from what i have read it is the blower motor resistor it goes bad and only lets the fan run on high google blower motor resistor and read on
If the fan only blows on high in the Liberty, check the blower resister. The resister circuit is the most likely cause.
Check the blower motor put the fan on and see if it blows on high if it doesn't replace the blower motor if it does blow high replace switch