Climate control has a mind of its own!

[Phase_K]

I have an '04 CV8 Monaro.

Mostly the Climate control works as it should. Occasionally though it seems to have a funny turn and completely ignores whatever I set it to and either blasts out cold air or hot air at full speed. At that stage it doesn't matter what I set the temperature to on the control it carries on blasting out the hot/cold air. The only way to stop it is to set it to 'Off'.

Next time I get in the car it is generally OK again, but this happens maybe a couple of times a week. Anyone experienced a similar issue?

Thanks!

[wozzza]

Mine always blasts hot air at your feet.

Everything else perfect can be lovely one minute it changes to your feet and it's gone from 20 degrees to what feels like 30 in a few seconds.

Curious if that's down to the heat of the engine etc.

[KMud]

Press the O/S Temp button - what does it say?

[Phase_K]

The outside temp button reports the outside temp correctly I believe. Certainly I have never noticed it being wildly out thats for sure. I will check the OS temp next time it plays up. Surely thats a difference sensor though anyway?

[SturdyHSV]

Phase_K said:

The outside temp button reports the outside temp correctly I believe. Certainly I have never noticed it being wildly out thats for sure. I will check the OS temp next time it plays up. Surely thats a difference sensor though anyway?

Possibly if it thinks the outside air is very cold, then it'll try to heat it up before blasting it into the cabin?

Or vice versa? I dno, just a thought!

[bigwheel]

SturdyHSV said:

Possibly if it thinks the outside air is very cold, then it'll try to heat it up before blasting it into the cabin?

Or vice versa? I dno, just a thought!

Correct.
If wildly inaccurate O/S temp displays on dash, replace O/S sensor. Clipped in front of the radiator left side, look through the bumper bar, as you stand with the engine in front of you.
Common Vauxhall/Opel part, about £12. Simples.

[KMud]

If it isn't the outside temp sensor, then I think the cabin one is the jobbie behind the instrument cluster bezel, bottom-left, single screw.

[granada203028]

My 05 CV8 had done this for a few years. Intermittently OK or looses it's temperature graduation. Cold is cold but anything else is hot. That is used in manual mode. Once I saw an "X" in heater display but only once. Can't see it being outside temp related or the air con side of things. Also I assume the simple manual mode is open loop, so no temperature measured any where matters. The set temperature is just used as a scale for 0 to 100%. As I think the heater has a water valve, I'm wondering if the air blending flap is sticking and it's the water valve still working which lets the air go cold.

The Monaro is not my everyday car now so reluctant to go chiselling up the heater trying to get to things unless there is a definitive explanation and cure published.