07 VZss ute air con problem

[Kelltza]

My 07 VZss ute has a odd problem with her air con, well at least i think its a problem......

When i turn it on and set it at the mode where the air is blowing threw the front vents to hit ya face, it can be running good, then all of a suden,it stops blowing from front vents and gos to top vents for ya windscreen.... so i have to turn it off then back on to get it back to the front vents.
Then other times it dose this it then also seems to slow down the power the car whilest driving ( but only wen it changes by itself to windscreen vents)
Also noticed today it would do it every time while driveing on an inclined angle road..... and also after an hours worth of driving with air con on, the car struggled with power to get up to speed, now i know some cars do this due to the aircon which is normal but we are talkingabout a v8 now, this shouldnt be overly that recognisable with a v8 6liter,

Any thoughts on wat is wrong....

 

[Fu Manchu]

One of the actuators will be faulty (most likely) and a vacuum leak will occur. The vacuum leak will be causing the power issues.

Start by looking at and checking the two actuators involved with your chosen settings. They will need to be removed and tested manually.

There is also a vacuum reservoir that could be leaking or the manifold that sits behind the dials. If it’s climate controlled, there’s a vacuum manifold right under and behind the glovebox, behind the fan area.

 

[Kelltza]

Thanks, i shall look into this..

 

[Jolls]

I have been reseaching this problem in my ute in preparation for resolving it in the next couple of days. From the manual:

Default Mode
Loss of Vacuum Supply to HVAC Unit
If a loss of vacuum occurs within the OCC system, the HVAC unit will default to the following settings. The ventilation
mode settings will remain constant regardless of what is displayed on the LCD screen (1), refer to Figure 2D – 27.
Regardless of recirculation switch (2) selection, the recirculation door (3) will remain closed allowing outside air (4) to
enter and flow into the HVAC unit via the plenum chamber inlet (5). The position of the air mix doors (6) will remain
controllable as their function is electrically operated by the air mix motor. Heated coolant will flow through the heater core
(7), as vacuum is required to maintain the water valve in the cold (closed) position. The fan switch (8) will operate the
blower fan (9) as normal. In any position of the mode switch (10), the face door (11) will remain closed. The demist/floor
door (12) will be positioned so that all air (13) leaving the HVAC unit will be directed to the demist ducts whether or not
the demist switch (14) is selected. Depending on the selected setting of temperature switch (15) and/or the MIN MAX
switch (16), this air may be cold, warm or hot air.

The guidance on removing, testing and reinstalling the vacuum solenoid pack is attached.

Best of luck - let us know how you go if you get to it before I do.

 

[Fu Manchu]

I would suggest that if the HVAC has to ever be removed, buy one from a wrecker, overhaul it. That's disassemble, deep clean, new seals, new evap, new heater core. Then the whole job is done fairly quickly.

 

[Jolls]

I trust both our problems are simple vacuum issues; otherwise I will take your advice.

 

[Jolls]

Hi mate,

Fixed mine today in arounf 10 minutes. Detail is here.

I trust your's is just a simple to fix.