Does anyone have an answer as to why my air conditioning fan controls - front and rear - only function on high? This problem started yesterday - 120,000 miles on this one owner vehicle.

 

Typically the front would be a burned out Blower resistor....High speed is direct voltage that Bypasses the internal resistance.... Very common issue...

The rear....Also has a resistor, But Ive never actually seen one fail.....Carefully look at where your rear fan speed switch is set on the dashboard....If it is set to driver control, the rear switches will not affect the fan speed.

 

Apologies for taking so long to post thanks - have been travelling. Appreciate your taking the time to respond.