VF AC cutting in/out when braking

[Super Coach]

Might sound abit weird but when I am braking and I get to a certain brake point (between 20-30km/h slowing down before coming to a complete stop) I can hear my fan cut out for a split sec (like it has a hiccup), only to come back on but then the AC doesnt blow cold air, its just warm. When I start moving again the air turns cold again from the AC. Its got me beat as I cant see anything that would be causing this. I did buy anew HVAC panel to swap out incase it is something internal, but I have to say my AC only seems to work well sometimes on auto. Sometimes the aircon doesnt seem cold on 16 but then on other days it does. The vehicle is a MY16 V6 Calais V, my other VF'S are both V8 sedans and I dont have this issue with them.

 

[stooge]

Might sound abit weird but when I am braking and I get to a certain brake point (between 20-30km/h slowing down before coming to a complete stop) I can hear my fan cut out for a split sec (like it has a hiccup), only to come back on but then the AC doesnt blow cold air, its just warm. When I start moving again the air turns cold again from the AC. Its got me beat as I cant see anything that would be causing this. I did buy anew HVAC panel to swap out incase it is something internal, but I have to say my AC only seems to work well sometimes on auto. Sometimes the aircon doesnt seem cold on 16 but then on other days it does. The vehicle is a MY16 V6 Calais V, my other VF'S are both V8 sedans and I dont have this issue with them.

get the gas level checked, when it gets low and you turn/brake it will cause the system to cut out because it thinks there is no ac gas.
you probably have a leak and if you leave it eventually it will stop totally.

 

[Super Coach]

get the gas level checked, when it gets low and you turn/brake it will cause the system to cut out because it thinks there is no ac gas.
you probably have a leak and if you leave it eventually it will stop totally.

Ok thanks, will do. Anyone particular in Adelaide worth seeing or is my AC Delco Holden Service centre the best place to go?

 

[stooge]

Ok thanks, will do. Anyone particular in Adelaide worth seeing or is my AC Delco Holden Service centre the best place to go?

Most automotive ac mechanics will be able to do it.

 

[Super Coach]

Ok so just an update to the problem. I am abit old school and switch the AC off before switching off the fan, to let the gases etc clear the lines.

I pressed the snow flake button to switch the AC off before I pulled into the driveway, I let the system run as I got the kids out and I noticed the AC was still going blowing cold air and I could hear the compressor running in the engine bay even though I had switched it off. It did this for a good 3-4min.

So the AC button is not switching it on or off for me. Where do I have to look to fix this issue. Is there a fuse? Or is it in fact the HVAC controls which I need to replace with a new unit/module? I already have a brand new one ready to go

 

[stooge]

So the AC button is not switching it on or off for me. Where do I have to look to fix this issue. Is there a fuse? Or is it in fact the HVAC controls which I need to replace with a new unit/module? I already have a brand new one ready to go

the whole system is computer controlled so when you push the button to turn the ac on or off it is not like older vehicles where it is a analogue control command(on/off) on these newer systems the computer will check various sensors and do what it likes according to those conditions.

when you mention "hvac controls" is you are referring to the button module on the inside of the vehicle that is below the mylink then replacing that is not going to do much as it is just a button panel that interfaces with the hcm, that button panel contains no logic it is just a button panel and digital display for the temperature setting.

the very first step i would be taking is getting the unit tested for the level of gas and leaks, the system will play up when the level is low because it has self protection logic built into the software controlling it.

you mentioned it is a my16 so the system is 8 years old now and leaks are not uncommon for a system of that age.

 

[stooge]

if you mean this part when you mentioned hvac controls then you could try and change it but i think it is vin locked but i am not sure on that.

 

[lordsnipe]

So the AC button is not switching it on or off for me.

Did you have the recirculate option selected? One thing I don't like with the Commodore is that the recirc option automatically turns on the air conditioning. Stupid Holden logic.

 

[lmoengnr]

Did you have the recirculate option selected? One thing I don't like with the Commodore is that the recirc option automatically turns on the air conditioning. Stupid Holden logic.

It's a climate control system.
Why turn it off?

 

[Super Coach]

no i leave it in auto, i dont touch the recirculate button. I will get it looked at soon. I bought the new HVAC control and assembly because who ever owned the car before hadn stuffed up the rotating knob for the fan and it wouldnt turn nicely, so i bought a spare but havent had a chance to do the swap.

My VF1 Redline and MSE dont have any AC problems (touch wood)