Four Seasons 37800 Engine Cooling Fan Temperature Switch

Engine Cooling Fan Temperature Switch

Four Seasons Temperature Switch 37800 is a radiator-mount engine cooling fan temperature switch built for direct temperature-based fan control. It uses a single male terminal and a system-mount design to help trigger cooling fan operation at the specified temperature point.

Compatible with select Mercedes-Benz and Nissan applications, including Mercedes-Benz 300D, 300TD, 300SD, 300SEL, 380SL, 380SEC, 380SE, 380SEL, 500SEC, 500SEL, 190E, and Nissan Maxima applications listed below. Four Seasons 37800 is an OE-spec replacement that meets or exceeds OEM requirements.

• Temperature switch for radiator-mounted cooling fan control
• Single-terminal, male connector design
• System mount installation style
• Temperature on point: 212
• Meets or exceeds OEM requirements
• Cross-reference part numbers include A14150 and SW4902

Product Details

Four Seasons Temperature Switch line components are built for temperature-sensitive engine cooling systems where accurate fan activation matters. Part number 37800 is a temperature switch type unit with a radiator mount description and a 212 temperature-on specification, making it a direct-fit style replacement for vehicles that rely on a threaded coolant temperature trigger at the radiator or cooling circuit. This Four Seasons 37800 temperature switch is listed for Mercedes-Benz 300D, Mercedes-Benz 300TD, Mercedes-Benz 300SD, Mercedes-Benz 380SL, Mercedes-Benz 380SEC, Mercedes-Benz 380SE, Mercedes-Benz 380SEL, Mercedes-Benz 500SEC, Mercedes-Benz 500SEL, Mercedes-Benz 190E, and Nissan Maxima applications.

This part cross-references A14150 and SW4902 for the same application.

Common Cooling System Issues

• Cooling fan does not switch on at the correct temperature
• Fan operation becomes inconsistent during stop-and-go driving
• Engine temperature rises when the radiator fan is not triggered properly
• Faulty temperature switch causes delayed fan engagement
• Cooling system warning signs tied to radiator-mounted switch failure

Installation Notes

Install this temperature switch at the radiator or system-mount location specified by the vehicle application. Verify connector style before installation: this unit uses a male terminal with one terminal position. Confirm the fan activation temperature and thread or mounting style against the original part before replacement. For Mercedes-Benz 300D, 300TD, and 300SD applications, as well as 380-series and 500-series models, match the existing switch location and electrical connection before service.

Quality Assurance

Four Seasons lists this part as meeting or exceeding OEM requirements, supporting OE-style fit and function for the specified cooling fan temperature switch applications.