Dodge Repair: resitor block, blower motor resistor, airbag deployment

Question
I have a 01 2500 dodge quad cab.fan only works on high. I changed
the switch , need to know if it might be the resitor block and how to change. thank you

Answer
Caret>REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIRBAGS, DISABLE THE AIRBAG SYSTEM BEFORE ATTEMPTING ANY STEERING WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. DISCONNECT AND ISOLATE THE BATTERY NEGATIVE (GROUND) CABLE, THEN WAIT TWO MINUTES FOR THE AIRBAG SYSTEM CAPACITOR TO DISCHARGE BEFORE PERFORMING FURTHER DIAGNOSIS OR SERVICE. THIS IS THE ONLY SURE WAY TO DISABLE THE AIRBAG SYSTEM. FAILURE TO TAKE THE PROPER PRECAUTIONS COULD RESULT IN AN ACCIDENTAL AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.

Disconnect and isolate the battery negative cable.
Reach under the passenger side end of the HVAC housing and unplug the wire harness connector from the blower motor resistor.
Remove the screws that secure the blower motor resistor to the HVAC housing.
Remove the blower motor resistor from the HVAC housing (BLOWER MOTOR/RESISTOR).