Universal Air SW9938C A/C Clutch Cycle Switch

Universal Air SW9938C Clutch Cycling Switch

The Universal Air SW9938C is an A/C clutch cycle switch for select GM trucks, SUVs, and passenger cars from the late 1980s through the mid-1990s. It is used in HVAC systems that rely on a clutch cycling switch to regulate compressor operation and maintain proper air conditioning performance.

Key Features

• Brand: Universal Air Clutch Cycling Switch line
• Part number: SW9938C
• Category: HVAC switch for A/C clutch cycling control
• Application-specific fitment for select Chevrolet and GMC vehicles
• Used on systems with system mount, round connector, and 2 terminals where noted
• Fits select applications with R-12 A/C system notes where listed

Detailed Description

The Universal Air SW9938C clutch cycling switch is built for vehicles that use an A/C pressure or cycling control strategy to engage and disengage the compressor clutch based on system conditions. This part number is listed for a wide range of Chevrolet Blazer, C/K truck, R/V truck, Suburban, and GMC C/K, R/V, Jimmy, and Yukon applications, plus 1990-1993 Buick Regal. For buyers searching for a clutch cycling switch for 1989-1993 Chevrolet C1500, a GMC K1500 clutch cycling switch, or a 1992-1993 GMC Yukon A/C clutch cycle switch, SW9938C is the referenced part number to verify against the vehicle’s connector and system configuration.

This part cross-references OE number 52457854 for the same application.

What It Helps Fix

• A/C compressor clutch that cycles incorrectly
• Intermittent compressor engagement
• Air conditioning that shuts off too soon or runs inconsistently
• Pressure-control issues tied to the cycling switch circuit
• Loss of cooling performance caused by a faulty HVAC switch

Installation Notes and Tips

• Verify the vehicle year, make, and model against the listed fitment before ordering.
• Match the connector style and terminal count; listed applications include round connector and 2-terminal configurations.
• Confirm system mount and A/C system details, including the R-12 note where specified.
• Inspect the connector, wiring, and nearby HVAC components before installing the new switch.
• After installation, test compressor cycling and cooling operation to confirm proper system response.

Quality Assurance

Universal Air identifies this part within its Clutch Cycling Switch product line for HVAC service applications. Use the listed fitment details and part number SW9938C to confirm the correct replacement for your vehicle.