Four Seasons 35820 A/C Clutch Cycle Switch

Temperature Switch for A/C Cycling Control

The Four Seasons Temperature Switch, part number 35820, is a system-mounted A/C clutch cycle switch built for 12-volt HVAC applications. It uses a driver-adjustable knob and a metal body with an open blade connector for straightforward temperature-based cycling control.

Key Features

• Four Seasons Temperature Switch, Brand Line: Temperature Switch
• Part number 35820 for A/C clutch cycle switch applications
• Driver adjustable knob for temperature control
• Metal construction with metal color finish
• 2-terminal open blade connector
• System mount design
• Cycling style temperature switch
• 12-volt electrical specification
• Cap tube length: 16 in. (406.4 mm)
• Meets or exceeds OEM requirements

Product Details

This Four Seasons A/C clutch cycle switch is used in temperature-controlled HVAC systems that cycle the compressor based on temperature thresholds. It is specified with a 26-degree off setting and a 33-degree on setting, helping regulate compressor engagement in the system. The metal construction, 2-terminal layout, and open blade connector support direct replacement use in older automotive HVAC setups. This part number 35820 also cross-references Four Seasons 57517 for the same application.

Vehicle Fitment

• Fits 1973-1979 Honda Civic, N/A. New Part; Temperature Switch.
• Fits 1967-1971 Ford Mustang, N/A. New Part; Temperature Switch.
• Fits 1971 Mercury Capri, N/A. New Part; Temperature Switch.
• Fits 1967-1971 Mercury Cougar, N/A. New Part; Temperature Switch.
• Fits 1968-1971 Mercury Montego, N/A. New Part; Temperature Switch.
• Fits 1968-1970 Mercury Marquis, N/A. New Part; Temperature Switch.

Common Replacement Reasons

• Inconsistent A/C compressor cycling
• Compressor staying engaged too long or not cycling properly
• Temperature switch electrical connection issues
• HVAC system temperature control faults
• Replacement for worn or failed system-mounted switch

Installation Notes

Verify the vehicle’s HVAC configuration, connector style, terminal count, and cap tube routing before installation. This switch is a system-mount, 12-volt component with an open blade connector, so matching the original electrical and mounting layout is important for proper operation. Confirm the temperature on/off settings and cap tube length against the original part before service.

Quality Assurance

Four Seasons lists this temperature switch as meeting or exceeding OEM requirements. The part is built for direct-fit replacement use in supported Honda Civic, Ford Mustang, and Mercury applications.