VP Calais Weird climate control issues

[Makkasman01]

Hey guys, I just bought a VP Calais as a second car, and the climate control is doing all sorts of weird things. Firstly, it all works fine when the car is stopped. It doesn't matter if the car is in Drive under full stall, or in park on idle (or on full rev). If the car is stopped there is no issues. Once you start driving however, the Fresh and Recirc randomly jumps between the two, even with the climate control turned off. It changes between Feet and Head for no reason as well. And if you are driving for a length of time it seems to just stick the heater on your feet (not comfortable for a 7 hour drive in summer). Once you turn the climate control on, I noticed that whenever the feet/head and recirc/fresh change it drops the ambient temperature down to -30 degrees, but once you stop it starts reading the correct ambient. I thought it may have been the ambient sensor, but the heater stays on even with climate off.

I've changed the VAC ball under the guard, changed the main control unit in the console, and checked all the vac lines under the bonnet. There is no vacuum at the heater control module, but everywhere else is fine. I'm presuming the lack of vacuum there is what is causing the heater to come on all the time. I'm about to start pulling the console apart and check all the vacuum lines under there, but I am not overly hopefull.

Does anyone have any ideas what could cause something like this? I've never seen anything this strange before.

Thanks
Jay

[holden#1]

well my VS Calais had a similar problem.... caused by a vaccum hose that needed to be pushed on a bit harder to its connection on the vaccum switching unit behind the dash. there are various links around on this topic.