Four Seasons 37318 HVAC Binary Switch

Four Seasons 37318 Pressure Switch

The Four Seasons Pressure Switch 37318 is a system-mounted HVAC binary switch built for pressure-based compressor control. It uses a 4-terminal, male connector design with a 10mm x 1.25 female-thread fitting and a steel body for direct replacement service on select Audi applications.

Key Features

• Binary HVAC pressure switch for system-mounted applications
• Male connector with 4 terminals
• 10mm x 1.25 female-thread fitting
• Steel construction with black finish
• Comp open/closed: closed; fan open/closed: open
• Operate pressure: 190 psi low off, 240 psi low on
• Meets or exceeds OEM requirements

Product Details

Four Seasons 37318 is a pressure switch for HVAC systems that monitor refrigerant pressure and signal compressor and fan operation based on system conditions. This binary switch is a direct-fit style replacement for select 1996-1999 Audi A4, Audi A4 Quattro, Audi A8, and Audi A8 Quattro models. It is built as a system-mounted pressure switch with the specified thread size and terminal layout for service on the original HVAC circuit.

This part cross-references UAC SW10078C for the same application.

Common Issues This Part Can Address

• Compressor cycling caused by incorrect pressure switch operation
• HVAC system shutdown from a failed pressure signal
• Fan control issues tied to pressure switch input
• Intermittent A/C engagement on Audi A4 and Audi A8 platforms
• Fault codes related to refrigerant pressure monitoring

Installation Notes and Tips

• Verify the connector style, terminal count, and 10mm x 1.25 thread before installation.
• Confirm the replacement matches the original system-mounted switch location.
• Inspect the HVAC circuit and refrigerant system for related faults before replacing the switch.
• Use the vehicle service information for proper pressure-switch replacement procedures.

Quality Assurance

Four Seasons 37318 meets or exceeds OEM requirements and is engineered for direct replacement use in the listed Audi applications. The Four Seasons Pressure Switch line focuses on accurate pressure-based HVAC control for service parts that match original system specifications.