Testing Heater Control Valve

[Katiemc1989]

I've been told to test my heater control valve with a multi meter but I'm unsure what to do so could any one help me please

[btmaldon]

You can test the voltage of the connections going to the HCV. Disconnect the plug, find the live and earth with your multimeter, turn the ignition on, turn the heater dial to cold, check multimeter voltage, then turn dial to hot and check voltage again. If the heater control panel is working it should give you a zero reading and a 9 to 12v reading. Cant remember which is cold and which is hot but it is as simple as that.

To test the HCV get someone to turn the ignition on and turn the dial between hot and cold while you listen for the solenoid to click open and shut. Its easier if it is off the car as you can see the thing open and close.

When its stopped working you find it is either stuck open or stuck closed so you either get hot or cold and nothing in between. For the sake of £40 or less you may as well change it.