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
Most likely a failed blower resistor.
try replaceing the switch that controls the low to high for heater It's gonna be the blower motor resistor (near the blower motor).
blower motor resistor is burned out
try replacing the blower motor resistor
The blower motor speed resistor is burned out.
If you are saying the Blower Motor only works on high, then your problem is a defective Blower Motor Resistor Pack. Replace it.
The blower motor resistor pack is bad.
Most likely and bad blower motor resistor.
You most like have a bad blower motor resister.......
You most likely will have a bad blower resister........
blower motor resister is bad
Probably the blower motor resistor, check blower motor at the same time