Help your A/C compressor clutch cycle on and off at the right time with this Four Seasons switch, part number 35845. It is an A/C Clutch Cycle Switch / Thermostatic Switch that Four Seasons describes as a system-mounted, adjustable cycling temperature switch. It fits many vehicles, among them the 1975-1979 Ford F-150, 1979-1981 Ford Mustang and 1972-1979 Ford F-250, as a direct-fit replacement for the listed applications. See the "Vehicles it fits" section for the full list.
A thermostatic cycling switch senses temperature within the A/C system and switches the compressor clutch on and off, which helps keep the evaporator from icing up. The 35845 is listed under both names: A/C clutch cycle switch and thermostatic switch.
- OE-style connectors: designed for a straightforward plug-in connection to the vehicle's wiring.
- Quality contacts: intended to maintain proper electrical conductivity.
- Sealing components supplied: comes with the gaskets, O-rings or seals needed to replace the switch properly.
- Precision engineered: engineered and tested by Four Seasons and designed for years of trouble-free operation.
Four Seasons backs its products with more than 50 years of mobile A/C experience.
Signs this switch may need replacing include a compressor clutch that won't engage, cycles erratically or never cycles off, and an evaporator that ices up and reduces airflow. These symptoms can have other causes, so diagnose the system before replacing parts.
Product information is for general reference and may contain errors. See our Disclaimer.
Frequently Asked Questions
Is this the right Mustang switch for my 1979-1981 Ford Mustang?
The Four Seasons 35845 is listed as a direct-fit replacement for the 1979-1981 Ford Mustang. See the "Vehicles it fits" section for other listed years and vehicles.
What does an A/C clutch cycle switch do?
It senses temperature in the A/C system and cycles the compressor clutch on and off, which helps keep the evaporator from freezing up.
Is the 35845 an adjustable switch?
Yes. Four Seasons describes it as a system-mounted, adjustable cycling temperature switch.
What comes with this switch?
It comes with the gaskets, O-rings or seals needed to replace it properly, and it uses OE-style connectors.
What are signs of a bad thermostatic cycling switch?
Signs it may need replacing include a compressor clutch that won't engage, cycles erratically or never cycles off, or an iced-up evaporator. These can have other causes, so diagnose first.
