What would be the best on/off-temp for the thermoswitch?


Thermostat Switch - Circuit On At 100°F and Off At 85°F - Large Flange

Too low to display
  • Review
  • TAG : Mercury Quicksilver F629449-2 - Thermoswitch
  • The thermoswitch or coolant temperature switch is located just to the right of the throttle body (red arrow). You will need to drain the coolant level to below the switch; usually, removing the coolant from the expansion tank is enough (yellow arrow). If you need additional help please see our article on .

    1. Check the thermoswitch for continuity when the engine is just above normal operating temperature (probe the connector on the thermoswitch and the engine block itself). If continuity is not present, the thermoswitch is bad and must be replaced.2. If the thermoswitch is good, check the underhood relay by switching it for one like it (possibly for the clutch interlock). If the cooling fans now work (or, if you used the clutch interlock relay and now the car won't start) then replace the fan relay.3. If both the thermoswitch and relay are good, replace the radiator fan itself.

  • To replace the switch you will need to drain the coolant level to below the thermoswitch, but you do not need to drain it completely. Usually, removing the fluid from the expansion tank is enough, as the radiator is below the level of the thermoswitch and will not flow back up into it. Even removing the expansion tank fluid, you should be ready for some spillage of fluid and catch and dispose of it in accordance with your local regulations. If you have not replaced or flushed your system in over two years, this is a very good time to consider performing this work as well.

    The Mishimoto Thermoswitch Fan Switch replaces your OEM S2000 fan switch, allowing your radiator fan to activate at 80°C / 176°F degrees, 15°C / 59°F degrees lower than stock temperature. This will help prevent heat soak and prolong the life of all the components in your engine bay. Installation is simple with direct replacement to OEM switch.

    Re: Choosing the correct thermoswitch for my electric cooling fan
    Bill McCord
    East Peoria, Illinois, USA  
    1968 MG MGC GT

  • Re: Choosing the correct thermoswitch for my electric cooling fan
    Joern Mueller-Neuhaus
    Koenigsbrunn/Augsburg, Bavaria, Germany  
    1964 MG MGB
    1969 MG MGC GT

    Fenwal was founded on accurate, reliable Temperature Sensing, Control and Limiting. Our Original product, the THERMOSWITH® Temperature Controller is still widely used today, as is our Bimetal Temperature Limiting Thermostat and our DETECT-A-FIRE® Fire & Over heat Detectors – the World Standard in mechanical heat detectors.

oil cooler thermoswitch | Porsche Club of America

The thermoswitch or coolant temperature sensor on the Porsche 951 determines the temperature of the coolant and sends a signal that works with the radiator fans and the turbo coolant pump. If you are having trouble with an erratic turbo pump or fans or they are not coming on, one of the first things you should check is the thermoswitch.