Cooling System Switches, Sensors & Relays
- Walker Products®Engine Coolant Temperature SensorEngine Coolant Temperature Sensor by Walker Products®. This product is made of high-quality materials to serve you for years to come. Designed using state-of-the-art technology and with customers in mind. It will meet your needs and...High quality at an affordable priceExpertly made from premium materials$6.51 - $141.28
- gpd®Engine Coolant Temperature SensorEngine Coolant Temperature Sensor by gpd®. Want to keep your vehicle performing reliably? Then premium gpd aftermarket auto parts are right up your alley. They are manufactured from superior-quality materials and feature solid...Designed to meet/exceed OE fit, form and functionDurability tested on every new design$6.25 - $350.56
- ACDelco®GM Original Equipment™ Engine Coolant Temperature SensorGM Original Equipment™ Engine Coolant Temperature 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...Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$7.33 - $190.85
- Four Seasons®Coolant Temperature SensorCoolant Temperature Sensor by Four Seasons®. Products are engineered and tested to provide years of trouble free operation. Backed by over 50 years of mobile A/C experience, fix it once and fix it right with Four Seasons.OE quality parts from top original equipment and aftermarket manufacturersThe finest quality at a great price$9.18 - $225.85
- WVE®Engine Coolant Temperature SensorEngine Coolant Temperature Sensor by WVE®. Replace your worn-out or faulty component with this quality replacement from WVE. This product is designed and tested to ensure the ultimate in durability and functionality. Made to meet or...Excellent replacement for your worn-out factory partDesigned to keep your vehicle running reliably mile after mile$5.42 - $302.48
- ACDelco®Genuine GM Parts™ Engine Coolant Temperature SensorGenuine GM Parts™ Engine Coolant Temperature 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...Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$16.38 - $59.93
- ACDelco®Professional™ Engine Coolant Temperature SensorProfessional™ Engine Coolant Temperature 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,...Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$17.79 - $78.80
- Mopar®Engine Coolant Temperature SensorEngine Coolant Temperature Sensor by Mopar®. Extend the service life of your engine and make it running smoothly with this high-quality product by Mopar. This part was specially designed to maintain the efficiency and performance of...Carefully crafted from premium materialsExcellent corrosion and wear resistance$20.16 - $341.56
- Motorcraft®Engine Coolant Temperature SensorEngine Coolant Temperature Sensor by Motorcraft®. With today's complicated automotive engines, it is crucial to have the right cooling system components for accurate temperature control, pressure relief, and gasket seals. Motorcraft is...Made to keep your vehicle's engine running coolDesigned to maintain proper cooling level and prevent overheating$11.97 - $122.32
- Beck Arnley®Temperature SensorTemperature Sensor by Beck Arnley®. When investing in this superior product by Beck Arnley, expect to get the exact OEM look, function, and fit. The product was developed to stringent factory specifications and crafted using...OE quality products from top original equipmentTop quality materials$8.43 - $47.07
- Walker Products®Engine Coolant Temperature SenderEngine Coolant Temperature Sender by Walker Products®. This product is made of high-quality materials to serve you for years to come. Designed using state-of-the-art technology and with customers in mind. It will meet your needs and...High quality at an affordable priceExpertly made from premium materials$4.55 - $95.87
- Standard®Engine Coolant Temperature SensorEngine Coolant Temperature Sensor by Standard®. SMP's vision is to be the leading independent supplier to the automotive aftermarket, providing the highest quality products, competitive prices and the highest reputation for integrity to...Global manufacturer of automotive aftermarket productsDirect-fit OE replacement that ensures ease of installation$5.28 - $120.71
- Facet®Engine Coolant Temperature SensorEngine Coolant Temperature Sensor by Facet®. The electronic engine management system has become a fundamental element in modern motor vehicles. It works to prevent failures that might seriously compromise the safety of the driver....The reliable goods for increase of reliability of the carQuality equal, if not superior, to that of the original components$7.11 - $28.24
- Delphi®Engine Coolant Temperature SensorEngine Coolant Temperature Sensor by Delphi®. 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...Delphi temperature sensors are built with the latest OE technologySensors use durable, one-piece design$11.17 - $47.39
- NTK®Engine Coolant Temperature SensorEngine Coolant Temperature Sensor by NTK®. Designed utilizing the latest technology, this product by NTK features premium quality and will perform better than advertised. Perfect for your vehicle and lifestyle, it is manufactured to...Increases vehicle fuel economy and engine performance while decreasing vehicle exhaust emissionsDirect replacement$8.07 - $244.80
- TRQ®Engine Coolant Temperature SensorEngine Coolant Temperature Sensor by TRQ®. Replace your faulty engine coolant temperature sensor with the high-quality sensor from TRQ. The engine coolant temperature sensor is designed to fit, perform, and last as long as its factory...Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$18.95 - $24.91$19.95 - $25.95Save up to 5%
- ACDelco®Professional™ Engine Coolant Temperature SenderProfessional™ Engine Coolant Temperature Sender 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$15.16 - $53.65
- Motorcraft®Engine Coolant Temperature SwitchEngine Coolant Temperature Switch by Motorcraft®. Looking to maintain the top condition of your electrical system? Motorcraft are ready to help you! Just choose from their immense selection of premium replacement electrical parts...Direct OEM replacementMeets strict Ford Motor Company standards$19.64 - $134.86
- Four Seasons®Engine Coolant Temperature SenderEngine Coolant Temperature Sender by Four Seasons®. All products are engineered and tested to provide years of trouble free operation. Backed by over 50 years of car parts experience, fix it once and fix it right with Four Seasons.OE quality parts from top original equipment and aftermarket manufacturersThe finest quality at a great price$11.19 - $147.36
- Denso®Engine Coolant Temperature SensorEngine Coolant Temperature Sensor by Denso®. Denso has supplied quality relays to the OE automotive world for over 60 years. The very same performance and dependability are available across the replacement aftermarket with Denso First...Made to keep your vehicle's engine running coolDesigned to maintain proper cooling level and prevent overheating$53.27
- URO Parts®Coolant Temperature SenderCoolant Temperature Sender by URO Parts®. This superior part by URO is a great alternative solution to the costly factory equipment that will help you restore smooth and efficient operation of your vehicle. Thoroughly designed and...Designed to replace your worn out factory cooling partOptimizes engine cooling performance$4.51 - $19.43
- Standard®Coolant Temperature Sensor KitCoolant Temperature Sensor Kit by Standard®. For over 100 years, professional technicians have trusted Standard® to replace the failed OE part. Standard® manufacturers the highest-quality, best-performing parts for all import...Complete repair kit includes all necessary components to do the job right; a Coolant Temperature Sensor and a high-quality connectorHigh-quality materials withstand extreme conditions; brass and plastic$17.70
- Standard®Engine Coolant Temperature SwitchEngine Coolant Temperature Switch by Standard®. Standard is to be the leading independent supplier to the automotive aftermarket, providing the highest quality products, competitive prices and the highest reputation for integrity to all...OE quality parts from top original equipment and aftermarket manufacturersThe finest quality at a great price$11.00 - $52.49
- Standard®Intermotor™ Engine Coolant Temperature SenderIntermotor™ Engine Coolant Temperature Sender by Standard®. Standard is to be the leading independent supplier to the automotive aftermarket, providing the highest quality products, competitive prices and the highest reputation for...OE quality parts from top original equipment and aftermarket manufacturersThe finest quality at a great price$5.55 - $193.42
- Standard®Tru-Tech™ Engine Coolant Temperature SensorTru-Tech™ Engine Coolant Temperature Sensor by Standard®. When you're low on oil, coolant or some other fluid, you may be tempted to just run down to the local auto parts chain store. But before you waste your time and gas only to...OE quality parts from top original equipment and aftermarket manufacturersThe finest quality at a great price$6.49 - $22.84
- Rein®Coolant Temperature SensorCoolant Temperature Sensor by Rein®. Is your vehicle feeling down on power? Do you see dark puddles on the ground when you park? Is your CHECK ENGINE light on? Your engine may be in need of repair, but before you waste your time and gas...Made to keep your vehicle's engine running coolDesigned to maintain proper cooling level and prevent overheating$7.93 - $11.36
- NTC®Water Temperature SensorWater Temperature Sensor by NTC®. 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$24.64 - $75.37
- Elth®Engine Coolant Temperature SensorEngine Coolant Temperature Sensor by Elth®. 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...Made to keep your vehicle's engine running coolDesigned to maintain proper cooling level and prevent overheating$14.99 - $19.29
- United Motor Products®Engine Coolant Temperature SensorEngine Coolant Temperature Sensor by United Motor Products®. Keep your pride and joy operating as it should with this top-notch part from United Motors Products. It’s made using the finest materials and advanced manufacturing...Excellent replacement for your worn out factory partWill help make your vehicle running as good as new$6.70 - $26.56
- ACDelco®Professional™ Engine Coolant Temperature SwitchProfessional™ Engine Coolant Temperature 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 lifestyle,...Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$20.32 - $24.71
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.