How to Change the Thermostat in a Dodge Ram

Your Dodge Ram is most likely tough, but even a Ram can't operate correctly with a malfunctioning thermostat. If your Ram is overheating or blows cool air when you turn on the heater, it's time to check the thermostat. If it needs to be changed, set aside about an hour, and your Ram will be good as new.

  • Park your Dodge Ram facing downhill, if possible. Disconnect the negative battery cable. Loosen the drain plug on the bottom right side of the radiator. Attach a piece of garden hose to the plug to drain the coolant into a container. Reuse the coolant later if it is relatively clean and new.

  • Follow the upper radiator hose to the top of the engine block to find the thermostat housing if your Dodge Ram was manufactured before 2004. In later models, the thermostat housing may be located at the end of the lower radiator hose.

  • Use pliers or clamp tool to remove clip holding the radiator hose to the thermostat housing. Loosen bolts attaching the cover to the thermostat housing and remove.

  • Note the position of the old thermostat and remove. Install the new thermostat in exactly the same position. Scrape old gasket residue from the inside of the housing cover. Install the new gasket.

  • Reattach the thermostat housing cover and upper radiator hose. Fill the radiator with reserve or new coolant. Run your Dodge Ram with the heater blowing on high until the engine warms up. Check for leaks.