Four Seasons 20948 A/C Trinary Switch

Four Seasons 20948 Trinary Pressure Switch

The Four Seasons Pressure Switch line delivers system-mounted HVAC control for A/C clutch and compressor circuits. Part number 20948 is a 12-volt, 4-terminal trinary pressure switch with a gray oval male connector and 3/8" x 24 male fitting thread size for select Toyota, Lexus, and Acura applications.

Key Features

• System-mounted trinary pressure switch for A/C pressure monitoring
• 12-volt electrical design with 4 pin terminals
• Oval gray male connector with Weather Pack sealing
• Steel construction with male fitting and 3/8" x 24 thread size
• Open compressor circuit and closed fan circuit configuration
• Meets or exceeds OEM requirements

Product Details

Four Seasons 20948 is a system mounted trinary pressure switch used in HVAC A/C clutch and compressor control circuits. The trinary design monitors refrigerant pressure and helps manage compressor operation while also supporting fan control logic. This pressure switch is built with a steel body, pin terminals, and a male oval connector for direct replacement service on select vehicles. It cross-references UAC SW10003C for the same application.

Compatible With 1995-1999 Toyota Avalon, N/A; 1994 Lexus SC300, N/A; 1994 Lexus SC400, N/A; 1992-1993 Lexus ES300, N/A; 1992-1993 Lexus SC300, N/A; 1992-1993 Lexus SC400, N/A; 1992-1993 Toyota Camry, N/A; 1992-1993 Toyota Celica, N/A; 1988-1992 Acura Legend, N/A; 1992 Lexus LS400, N/A; 1991 Lexus LS400, N/A; 1991 Toyota Celica, N/A.

For Toyota Camry, Toyota Celica, Lexus SC300, and Lexus SC400 service, this part number 20948 supports pressure-switch replacement where the original system-mounted trinary switch is specified.

Common Issues This Part May Address

• A/C compressor not engaging due to pressure switch failure
• Intermittent compressor cycling from worn internal contacts
• Cooling fan control problems tied to pressure signal loss
• HVAC pressure circuit faults caused by damaged connector terminals
• Refrigerant system shutdown from an inoperative trinary switch

Installation Notes and Tips

Verify connector shape, terminal count, and fitting thread size before installation. Confirm the vehicle uses a system-mounted trinary pressure switch and match the original electrical and refrigerant-side configuration. Inspect the connector, terminals, and sealing surfaces for corrosion or damage before reconnecting the HVAC harness. After installation, check A/C operation and fan response under normal system pressure.

Quality Assurance

Four Seasons 20948 is listed as meeting or exceeding OEM requirements for the specified applications. The Four Seasons Pressure Switch line is built for direct-fit HVAC service where accurate pressure signaling is required for compressor and fan control.