The thermo switch in a Honda Accord is located either in the bottom of the radiator or in the coolant pipe located above the oil filter, depending on the year model. This switch senses the temperature of the coolant. Once the coolant reaches a certain temperature, the switch sends a signal to turn on the fans to reduce the coolant temperature to the desired level. When this switch fails, it can cause the fans to not operate, resulting in the engine overheating.
Place a drain pan under the radiator. Loosen the drain plug. Remove the radiator cap and allow the coolant to drain. Tighten the drain plug.
Disconnect the electrical connector from the thermo switch. Use a wrench to remove the switch.
Install and tighten the new switch. Connect the electrical connector.
Refill the coolant in the radiator and top off the coolant reservoir.
