Q: How to Replace an Air Conditioning Pressure Switch on Dodge Challenger?
A: It is not necessary to discharge the air conditioning system in order to replace the pressure switch. Disconnect the cable from the negative battery terminal. Unplug the electrical connector from the air conditioning pressure switch and unscrew the switch. Unscrew the pressure switch from the line, being careful not to damage the refrigerant line, and discard the O-ring seal. Lubricate a new R-134a or R-1234yf compatible O-ring seal with the appropriate refrigerant oil and place it into position. Screw the new switch onto the refrigerant line valve until hand-tight, and then tighten it securely. Reconnect the electrical connector and the battery cable.