Install a new blower motor resistor. Chronic problem across all GM vehicles. Usually located under passenger side dash, not a very expensive fix. Drop the blower motor cover, and the resistor should be easily accessible.
In general the heater blower motor speed resistor is located in close proximity to the blower motor.
The blower motor speed resistor is burned out.
The blower motor speed resistor is burned out. The high speed function bypasses the resistor. The speed resistor is generally located near to the blower motor.
You'll find the heater blower motor resistor in the heater/air conditioner compartment. This compartment is location underneath the dashboard. This is the part that allows the heater blower motor to change the fan's speed.
Blown fuse. Burned out blower speed resistor. Faulty blower switch. Bad blower motor.
there is a resistor that controls the speed and should be near the blower motor its called blower motor resistor
Blown fuse, defective Blower Motor Resistor Pack, Defective Blower Motor, or Defective Blower Motor speed control switch.
The blower motor speed resistor is burned out.
They generally locate the heater motor speed resistor nearby the blower motor because the resistor depends on the blower to keep it cooled.
bad blower resistor
If it has only high speed, the blower motor resistor has to be replaced to get all speeds back.
Normally when a heater blower motor only works on the High setting, it is caused by a defective Blower Motor Resistor Pack. The fix is to, Replace it. In very rare instances it can also be a defective blower motor speed control switch, but rarely.