Description Peterbilt Pressure Switch Replaces OEM: 18-03836 or P93CAA3606-1. Application: Peterbilt Description: Pressure Switch Fitting Style: Metric Wire Type: Pigtail use 1546 Type of Operation: N.O. Close-270 psi Open-200 psi Refrigerant Type: R143a Fitting Thread Size: Female M10-1.25 Note: 2 pin