Help protect your truck's air conditioning system with the Four Seasons switch, part number 35901, a system-mounted trinary pressure switch that monitors refrigerant pressure and controls when the A/C components run. It fits many commercial trucks, among them the 1990-1992 Kenworth K220, 1992-1993 Kenworth C540 and 1995-2003 Freightliner FL50, as a direct-fit replacement for the listed applications. See the Buyer's Guide tab for the full list.
A trinary switch is designed to handle three pressure functions in one unit. It opens the compressor circuit if system pressure drops too low or climbs too high, and it provides a mid-pressure signal commonly used to switch the condenser fan.
- Corrosion resistance: Zinc coated to help resist corrosion.
- Vehicle specific: Built for specific vehicle applications.
- Sealing parts included: Comes with the gaskets, O-rings or seals needed to properly replace the switch.
- Color coded: Color coding makes the switch easy to identify.
Four Seasons engineers and tests its products and brings more than 50 years of mobile A/C experience to its line.
Signs this switch may need replacing include a compressor that won't engage or cycles erratically, a condenser fan that doesn't come on, or warm air from the vents. These symptoms can have other causes, so diagnose the A/C system before replacing the switch.
