VE Series II Air Conditioner Problem

[Dillinium]

Hey,

So I am having an issue with the HVAC system in my 2011 Series II SV6 Commodore.

For some reason the cold and hot air is not mixing properly, I can only get hot air on max temp (H) and anything below that (30 degrees and down) is either cold air or ambient temperature air.

I have done a fair amount of research and found a couple of related forums/articles but nothing specific on my exact issue. A lot of what I have read seems to suggest the problem I have might be related to a possibly faulty actuator but I genuinely don't know. I have checked the heat/cool actuator on the passenger's side and that seems to be working fine as the HVAC arms connected to it are moving as I turn the temperature dial, the temperatures just don't actually change until I get to max.

Another thing I will add is that it seems to be an intermittent fault because I had the problem for a while and one day it fixed itself, the HVAC worked fine for maybe a month or so and the issue came back/

Any help or suggestions would be greatly appreciated.

 

[Skylarking]

Welcome to the forum.

Air outlet temperature is controlled by mixing the air that passes through the heater core and the air that passes through the ac evaporator so that you get the temp you want. This is accomplished by actuators to move flaps which adjust the air flow.

So you need to ensure all actuators are working as expected but the harder part is to ensure all flaps are moving as expected (the flaps are inside the hvac box so you can't see them move). The easiest 2st step may be to perform an actuator calibration reset process for the VE. Not sure the process but it involves holding some button down for a few seconds at startup. Someone should help with this reset process.

Even if the flaps inside the hvac box are moving as expected, there may be worn seals within or even some debris that has blocked some airflow through one or both of the heater core and ac evaporator. Cabin filters do have a real use here.

And thats just the meachanical side... How the air is blended to get to the desired temp depends on temp sensor measurents the system makes... Lots of temp sensors around. So you may need to connect diagnistic equipment to the car to check what the system is seeing in relation to temp readings as one or more may be wrong as they are failed sensors. Best also check for DTC's.

There are a few threads on teh subject of HVAC operation and fault finding and repair.

If the HVAC box needs to come out, it can be a hugely time consuming job though there is a thread that shortcuts the process somewhat. Having teh box out means all internals can be checked and repaired (something which is impossible with it in the vehcile).

Good luck.

 

[tlm2408]

Hold the rear demister button for about 3 seconds. If your fan is running you will hear it stop, a few seconds later the fan will start up again you will also hear the flaps moving.