A thermostat is a temperature-controlled switch that turns heat on or off in a machine. It is usually used in conjunction with a heat sink which is a device that absorbs and dissipates heat.
The thermostat acts as a sensing device that detects the temperature of the machine and compares it to a set point or target temperature. If the temperature of the machine is below the set point the thermostat energizes a switch that turns on the heat. If the temperature of the machine is above the set point the thermostat de-energizes the switch which turns off the heat.
A car thermostat is a temperature-controlled switch that turns the engine’s cooling system on or off. The thermostat is usually located in the engine coolant passage between the engine and the radiator.
The thermostat acts as a sensing device that detects the temperature of the engine coolant and compares it to a set point or target temperature. If the temperature of the engine coolant is below the set point the thermostat energizes a switch that turns on the engine’s cooling system. If the temperature of the engine coolant is above the set point the thermostat de-energizes the switch which turns off the engine’s cooling system.
The most common way to test a car thermostat is to use a digital multimeter.
1. Set the multimeter to the ohms setting.
2. Disconnect the negative (-) battery terminal to prevent accidental shocks.
3. Locate the thermostat. The thermostat is usually located in the engine coolant passage between the engine and the radiator.
4. Remove the thermostat. Consult your vehicle’s repair manual for specific instructions on how to remove the thermostat.
5. Inspect the thermostat for damage. Replace the thermostat if it is damaged.
6. Test the thermostat.
7. Reconnect the negative (-) battery terminal.