Provide your semi with reliable AC that activates when needed, with the OTR 12 V 30-40A 5-Terminal A/C Relay Switch with Expertise Built In™. This replacement relay sends electricity to the compressor clutch once directed by a user, activating the air conditioning system. Signs and symptoms of a failing relay include unexpected AC shutdowns, an unresponsive switch, or clicking noises. The air conditioning and heating system in heavy duty trucks has a major impact on drivers’ safety and comfort level. Whether you are looking for A/C compressors, condensers, driers, freon, or blower motors, FleetPride has the part you need to make sure your air conditioning and heating are well maintained. Keep your heavy duty fleet operations working as productively and efficiently as possible by finding the right air conditioning and heating part for you. FleetPride is your First Click in Heavy Duty®.