Defrost & heater scenarios

[TurboLove]

I have a '14 Cayenne GTS that I recently picked up.  Here's my first scenario: when I need to defrost the front interior window, I hit the 'defrost' button and it immediately starts to blow air on my front window.  Regardless what the temp is set at, it blows pretty hard and hot and it shows that the 'sync' button is on as well as the 'AC' is on too.    Even if the temp was last set at "Lo" and the AC turns on, it blows really hot air.   Is this normal??  

 

I have a situation, separate from the defrost scenario, when I just want to blow some hot air into the cabin. (It may be cold outside and want to heat the interior.)  I turn on the air toggle, adjust the temp to 74 degrees (hit 'sync' to have both sides in-sync) but I rarely get warm air to blow. (It will blow hard but not at the set temp.)  Even when the car is warmed up and driving.  I'll adjust the temp to 80 degrees, and it gets just a tad warmer but not very warm at all.  Anyone have an idea what is going on? 

 

What's really crazy about all this is apparently I don't have any hot air issue when I turn the defrost function on only when I turn the heat on in the cabin.   

Edited March 5, 2017 by TurboLove

[deilenberger]

I think spending a bit of time with your owners manual would be productive. What I don't understand is you apparently used to own a 957 Cayenne - and in my experience - the 958 HVAC system behaves much the same as the 957- with the exception that there is actually some heat sent to the drivers tootsies when called for.

 

The "Defrost" button is also a "Defog" function - and the behavior is EXACTLY what's expected and EXACTLY what your 957 should also have done. It's max temperature - all the heater is capable of - with the AC evaporator chilling and DRYING the air before it's heated by the heater core.

 

As far as your other problem - what is an "air toggle" that you're turning on?  I suspect if you set the HVAC to AUTO mode, and simply adjust the temperature the system will do exactly what you hope and want it to. In AUTO mode it will speed up the fan and crank up the heat in response to an increase in the desired temperature setting. When the interior of the car reaches the desired setting it will turn down the fan and lower the heat in order to KEEP it at that requested temperature. This is all assuming that engine is hot. If you just started the vehicle - the fan doesn't increase much in speed since  the engineers figured it was better to NOT blow cold or cool air at you when you're asking for hot air.

 

I don't think you have any problem - except understanding how the system works. Mine sits in AUTO mode on both sides, the temperature set to 72F, pretty much all the time. On very rare occasions I find it necessary to press the DEFROST button - but after it's defrosted and I press the button again it reverts to the same mode it was in, AUTO @ 72F.

Edited March 6, 2017 by deilenberger