Always wear safety glasses when working on your vehicle. Wear other personal protective equipment (PPE) when necessary, for example latex gloves or closed toe shoes.
1.Start the engine and allow it to warmup. Turn on the heater.
2.Move the heater temperature switch from cooler to hotter and check for a change in air temperature.
3.Turn off the engine. Open the hood and locate the heater control valve. It is usually mounted to the firewall on the passenger side.
4.Verify that the temperature control cable is connected to the heater control valve and the valve is opening and closing. Check for coolant leaks at the valve.
5.Allow the engine to cool down.
6.Disconnect the control cable from the heater control valve.
7.Disconnect the heater hoses from the heater control valve.
8.Remove the old heater control valve.
9.Install the new heater control valve.
10.Reconnect the heater hoses and the control cable.
11.Refill the radiator and overflow reservoir with coolant.
12.Pressure test the cooling system and check for any leaks. Top off coolant in the radiator.
13.Install the radiator cap.
14.Start the engine and allow it to warmup. Turn on the heater and move the temperature switch from cooler to hotter. Verify that hot air is coming out.