VF Series II SS Heater ineffective or intermittent.

[John Eric]

The heater on my VF Ute is intermittent at best or straight out ineffective and does not deliver the required heat as per set temperature. Cold or cool air at the same time is not unusual.

 

[Forg]

Before getting too troubleshootey … is this issue mostly obvious during the first 15-odd minutes of driving, and at this time of year when the set temp isn’t super far away from the temps outside? And when the set temp is heaps away from outside temps (eg. mid winter or mid summer) does it work fine?

Holden (or maybe GM Accountants) ditched a few sensors which the HVAC system (from the GM parts-bin) can kinda/sorta extrapolate; but not that well. I find this time of year to be a bit sucky, I get cold air blown on me for no good reason when driving in the morning, and I think it’s a design problem not something malfunctioning.

 

[John Eric]

Well let me put it this way without getting to judgy, last night, a forty five minute trip, outside temp. 5 deg. Inside asking for 23 deg both zones, and lucky to get any heat at all. Yet on other occasions it has been quite effective and has delivered as requested so clearly it is a bit intermittent in regard to delivering. I do like the AC on most of the time but AC on or off does not make any different. Having the AC on reduced interior fogging of course.

 

[stooge]

gm hvac in the ve/vf is notoriously garbage imo.

in every ve/vf i have owned 10+ every one of them the temp settings were garbage, you would set it at say 22 and it would be cold then change to 24 and it would be way too hot.
it was always hard to find the middle ground and then it could just decide to change on its own.
the zb was similar but not as bad.

 

[Forg]

Well let me put it this way without getting to judgy, last night, a forty five minute trip, outside temp. 5 deg. Inside asking for 23 deg both zones, and lucky to get any heat at all. Yet on other occasions it has been quite effective and has delivered as requested so clearly it is a bit intermittent in regard to delivering. I do like the AC on most of the time but AC on or off does not make any different. Having the AC on reduced interior fogging of course.

No I agree with you, there‘s something wrong beyond the normal GM cheapskatery there.

 

[Skylarking]

Maybe the cogs that turn the blender door are stuffed so the motor sometimes turns the door and others times doesn’t which results in an inability to correctly control the temperature.If you hear the blender motor operating and the gears within the hvac grinding that may be the hint to look at this area…

I can’t remember how to do a hvac door/vane motor calibration… Doing such could help as could google in finding the procedure.

 

[John Eric]

To do this first close your doors and turn the radio off. You’ll need to listen to the motors and they’re very quiet. Turn the Ignition to ‘on’ but do not start the car. Press and hold the rear demister button until you hear the actuators moving. After 10-15 seconds the actuators will stop and the system will be calibrated.

 

[RevNev]

last night, a forty five minute trip, outside temp. 5 deg. Inside asking for 23 deg both zones, and lucky to get any heat at all.

It depends on the interior temperature, how close that is to the set temperature determines how hot or cold and the volume of air blowing from the vents. It's not a perfect climate control system but I'd consider it's reasonable but sometimes you need to crank it up when extra cold or lower the settings on a hot day.

 

[lmoengnr]

To do this first close your doors and turn the radio off. You’ll need to listen to the motors and they’re very quiet. Turn the Ignition to ‘on’ but do not start the car. Press and hold the rear demister button until you hear the actuators moving. After 10-15 seconds the actuators will stop and the system will be calibrated.

Does that work for a VF as well as a VE?

 

[John Eric]

Does that work for a VF as well as a VE?

That is for a VF according to Google.