Cooling System Switches, Sensors & Relays
- ACDelco®GM Genuine Parts™ Engine Cooling Fan Motor RelayGM Genuine Parts™ Engine Cooling Fan Motor Relay by ACDelco®. GM Genuine Parts Wiring Relays are designed, engineered, and tested to rigorous standards, and are backed by General Motors. These relays help connect or disconnect power...Helps connect or disconnect power to vehicle accessoriesSome GM Genuine Parts may have formerly appeared as ACDelco GM Original Equipment (OE)$34.57
- ACDelco®GM Original Equipment™ Auxiliary Engine Cooling Fan RelayGM Original Equipment™ Auxiliary Engine Cooling Fan Relay by ACDelco®. Designed utilizing the latest technology, this product by ACDelco features premium quality and will perform better than advertised. Perfect for your vehicle and...Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$20.30 - $67.29
- ACDelco®GM Original Equipment™ Engine Coolant Level ModuleGM Original Equipment™ Engine Coolant Level Module by ACDelco®. Designed utilizing the latest technology, this product by ACDelco features premium quality and will perform better than advertised. Perfect for your vehicle and...Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$30.12 - $130.40
- ACDelco®GM Original Equipment™ Engine Coolant Level SwitchGM Original Equipment™ Engine Coolant Level Switch by ACDelco®. Designed utilizing the latest technology, this product by ACDelco features premium quality and will perform better than advertised. Perfect for your vehicle and...Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$17.65 - $106.48
- ACDelco®GM Original Equipment™ Engine Cooling ConnectorGM Original Equipment™ Engine Cooling Connector by ACDelco®. Designed utilizing the latest technology, this product by ACDelco features premium quality and will perform better than advertised. Perfect for your vehicle and lifestyle,...Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$1.68 - $97.22
- ACDelco®GM Original Equipment™ Engine Cooling Fan Switch ConnectorGM Original Equipment™ Engine Cooling Fan Switch Connector by ACDelco®. Designed utilizing the latest technology, this product by ACDelco features premium quality and will perform better than advertised. Perfect for your vehicle and...Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$23.32 - $35.48
- ACDelco®GM Original Equipment™ Temperature Sensor O-RingGM Original Equipment™ Temperature Sensor O-Ring by ACDelco®. Designed utilizing the latest technology, this product by ACDelco features premium quality and will perform better than advertised. Perfect for your vehicle and lifestyle,...Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$4.37 - $6.78
- ACDelco®Genuine GM Parts™ Engine Coolant Level SensorGenuine GM Parts™ Engine Coolant Level Sensor by ACDelco®. Designed utilizing the latest technology, this product by ACDelco features premium quality and will perform better than advertised. Perfect for your vehicle and lifestyle, it...Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$24.72 - $151.07
- ACDelco®Professional™ Engine Coolant Temperature Sensor ConnectorProfessional™ Engine Coolant Temperature Sensor Connector by ACDelco®. Designed utilizing the latest technology, this product by ACDelco features premium quality and will perform better than advertised. Perfect for your vehicle and...Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$9.66 - $17.77
- ACDelco®Professional™ Engine Cooling Fan Motor RelayProfessional™ Engine Cooling Fan Motor Relay by ACDelco®. Designed utilizing the latest technology, this product by ACDelco features premium quality and will perform better than advertised. Perfect for your vehicle and lifestyle, it...Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$12.22 - $37.05
- ACDelco®Professional™ Water Pump RelayProfessional™ Water Pump Relay by ACDelco®. Designed utilizing the latest technology, this product by ACDelco features premium quality and will perform better than advertised. Perfect for your vehicle and lifestyle, it is manufactured...Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$29.18
- Dorman®Coolant Temperature Sensor ConnectorsCoolant Temperature Sensor Connectors by Dorman®. Dorman offers a comprehensive line of Engine Coolant Temperature Sensor Connectors for a wide range of applications. All Dorman's Engine Coolant Temperature Sensor Connector are...Made to keep your vehicle's engine running coolDesigned to maintain proper cooling level and prevent overheating$4.43 - $21.76
- Dorman®Cooling Fan Relay KitCooling Fan Relay Kit by Dorman®. Designed to restore the radiator fan to proper operation by reliably controlling fan speeds, Dorman's Engine Cooling Fan Motor Relay provides long lasting protection against overheating. It is...Wire harness included for a complete repairDirect replacement for a proper fit$32.48 - $51.77
- Dorman®Cooling Fan Resistor KitCooling Fan Resistor Kit by Dorman®. Designed to restore the radiator fan to proper operation by reliably controlling fan speeds, Dorman's Engine Cooling Fan Motor Relay provides long lasting protection against overheating. It is...Wire harness included for a complete repairDirect replacement for a proper fit$25.67 - $31.78
- Dorman®Cooling System Retaining ClipsCooling System Retaining Clips by Dorman®. Engine Coolant Temperature Sensor Clips holds the coolant temperature sensor in place. All Dorman's Engine Coolant Temperature Sensor Clips are made of high quality materials for durability.Often lost during servicingEasy to install$4.80
- Dorman®Engine Coolant Radiator Fan ModuleEngine Coolant Radiator Fan Module by Dorman®. Dorman offers a comprehensive line of Radiator Fan Modules for a range of applications. All the Radiator Fan Modules are constructed from high-quality materials for long-lasting durability.Easy to installDirect replacement for a proper fit$69.50 - $247.29
- Dorman®Engine Coolant Temperature Sensor ConnectorEngine Coolant Temperature Sensor Connector by Dorman®. Dorman offers a comprehensive line of Engine Coolant Temperature Sensor Connectors for a wide range of applications. All Dorman's Engine Coolant Temperature Sensor Connector are...Vehicle try-on testing has been conducted on this part to ensure a trouble-free performanceEasy installation - just splice in the new socket to your existing wiring$28.49
- Dorman®Engine Cooling Fan MotorEngine Cooling Fan Motor by Dorman®. Increase the life of your vehicle's engine by keeping your cooling system in top condition. Replace your faulty engine cooling component with this highly efficient replacement product and be sure the...Made to keep your vehicle's engine running coolDesigned to maintain proper cooling level and prevent overheating$32.60 - $36.37
- Dorman®OE Solutions™ Engine Coolant Temperature SensorOE Solutions™ Engine Coolant Temperature Sensor by Dorman®. This engine coolant temperature sensor is designed to match the fit and function of the original sensor on specified vehicles, and is engineered for durability and reliable...Direct replacement - this engine coolant temperature sensor is designed to match the fit and function of the original sensor on specified vehiclesIdeal solution - this sensor is a reliable replacement for an original part that has failed due to fatigue or electrical malfunction$32.72
- Dorman®Radiator Fan ModuleRadiator Fan Module by Dorman®. Dorman offers a comprehensive line of Radiator Fan Modules for a range of applications. All the Radiator Fan Modules are constructed from high-quality materials for long-lasting durability.Easy to installDirect replacement for a proper fit$69.50 - $247.29
- Dorman®Radiator Fan Motor Wiring HarnessRadiator Fan Motor Wiring Harness by Dorman®. Dorman offers a comprehensive line of Radiator Fan Motor Wiring Harnesses for a wide range of applications. All Dorman's Radiator Fan Motor Wiring Harnesses are constructed of high-quality...No special tools required for installationEasy to install$20.39 - $25.36
- Genuine®Auxiliary Fan ResistorAuxiliary Fan Resistor by Genuine®. If your engine cooling system is in need of repair, don’t compromise the performance and safety of your car with suspect, off-brand replacement parts from the local auto parts chain store. On our...Designed to restore your vehicle’s engine cooling systemGenuine OE replacement parts from the OE manufacturer$69.11 - $215.36
- Genuine®Coolant Level SensorCoolant Level Sensor by Genuine®. If your engine cooling system is in need of repair, don’t compromise the performance and safety of your car with suspect, off-brand replacement parts from the local auto parts chain store. On our...Designed to restore your vehicle’s engine cooling systemGenuine OE replacement parts from the OE manufacturer$42.84 - $213.92
- Genuine®Cooling Fan RelayCooling Fan Relay by Genuine®. If your engine cooling system is in need of repair, don’t compromise the performance and safety of your car with suspect, off-brand replacement parts from the local auto parts chain store. On our...Designed to restore your vehicle’s engine cooling systemGenuine OE replacement parts from the OE manufacturer$27.71 - $118.50
- Genuine®Engine Coolant Radiator Sensor PlugEngine Coolant Radiator Sensor Plug by Genuine®. If your engine cooling system is in need of repair, don’t compromise the performance and safety of your car with suspect, off-brand replacement parts from the local auto parts chain...Designed to restore your vehicle’s engine cooling systemGenuine OE replacement parts from the OE manufacturer$4.72
- Genuine®Engine Coolant Sensor O-RingEngine Coolant Sensor O-Ring by Genuine®. If your engine cooling system is in need of repair, don’t compromise the performance and safety of your car with suspect, off-brand replacement parts from the local auto parts chain store. On...Designed to restore your vehicle’s engine cooling systemGenuine OE replacement parts from the OE manufacturer$4.65
- Genuine®Engine Coolant Temperature Sender O-RingEngine Coolant Temperature Sender O-Ring by Genuine®. If your engine cooling system is in need of repair, don’t compromise the performance and safety of your car with suspect, off-brand replacement parts from the local auto parts...Designed to restore your vehicle’s engine cooling systemGenuine OE replacement parts from the OE manufacturer$7.73
- Genuine®Engine Coolant Temperature Sensor ConnectorEngine Coolant Temperature Sensor Connector by Genuine®. If your engine cooling system is in need of repair, don’t compromise the performance and safety of your car with suspect, off-brand replacement parts from the local auto...Designed to restore your vehicle’s engine cooling systemGenuine OE replacement parts from the OE manufacturer$1.24 - $10.53
- Genuine®Engine Coolant Temperature Sensor O-RingEngine Coolant Temperature Sensor O-Ring by Genuine®. If your engine cooling system is in need of repair, don’t compromise the performance and safety of your car with suspect, off-brand replacement parts from the local auto parts...Designed to restore your vehicle’s engine cooling systemGenuine OE replacement parts from the OE manufacturer$2.62 - $10.89
- Genuine®Engine Cooling Fan ControllerEngine Cooling Fan Controller by Genuine®. If your engine cooling system is in need of repair, don’t compromise the performance and safety of your car with suspect, off-brand replacement parts from the local auto parts chain store. On...Designed to restore your vehicle’s engine cooling systemGenuine OE replacement parts from the OE manufacturer$238.64 - $723.88
The way many systems operate in your vehicle is dependent on the engine coolant temperature, making cooling system switches and sensors very important parts. These components provide an input to the engine control module (ECM), which in turn regulates fuel, ignition and other vehicle functions based on temperature and the input from other sensors. Coolant sensors and switches are threaded into coolant passages, where they are directly exposed to coolant for the most accurate temperature measurement in order to provide the engine control module with real time data.
Coolant switches are used when a simple on/off signal is needed, as in the early fuel evaporation (EFE) system, which is used on some carbureted vehicles to heat the fuel mixture when the engine is cold to improve vaporization. In this system, a plate, with a heater grid under one or both carburetor barrels, is installed between the carburetor and the intake manifold. A temperature switch grounds the EFE circuit when the vehicle is cold and a relay supplies power to the heater grid. When the engine reaches a specified operating temperature, the switch opens, deactivating the relay and shutting off the heater grid.
When a range of coolant temperature data is required, a coolant temperature sensor is needed. A common use for these data would be for a temperature gauge. Most coolant temperature sensors are thermistors, which change resistance according to temperature. Most of these are NTC (negative temperature coefficient) thermistors, which decrease resistance as temperature increases. The ECM sends a 5-volt reference voltage to the sensor and the sensor’s resistance reduces the voltage sent back to the computer. The temperature is calculated by the ECM based on the return voltage.
The ECM uses temperature data from the coolant temperature sensor to: vary injector pulse width, increasing on-time for a richer mixture when the engine is cold, and decreasing on-time as the engine warms up; increase idle speed when the engine is cold, to prevent stalling; and turn the electric cooling fan on and off. In addition, coolant temperature information is critical because certain component function must only be enabled when the engine is warm. These include the EGR (exhaust gas recirculation) system, which would cause the engine to run rough and stall if exhaust gas was introduced to the intake when the engine is cold; the evaporative emissions control purge valve; and the transmission torque converter clutch.
Some of the engine cooling system components, for example, a radiator fan, draw a high current from the power source. If you connect them directly or using a switch to the alternator or the battery, it may cause a short circuit, which can result in a fire or damage to the battery. To avoid such a turn of events, virtually all electric engine cooling system components are connected to the circuit through a relay. It is a small electromagnetic switch operated by a relatively small electric current that can turn on or off a much larger electric current. This allows to power any energy-intensive devices without running the risk of damaging the battery or other vehicle components. Relays vary in size and construction, while their operating principle remains the same.