front windshield defroster temperature
10-23-2003, 04:18 PM
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front windshield defroster temperature
I turned on my front windshield defroster this morning (it was snowing) and the air that was being blown out was HOT! Could only stand to run the front defroster for less than a minute before it was so uncomfortable that had to shut it off.
The A/C had been on 70deg F on AUTO. I pushed the front windshield defrost button, the fan went to full and the air coming out, hitting the windshield and blowing on my face was uncomfortably hot. Turning down the temperature control to 64 didn't change the air temperature. Only when I turned the temp to LO did the air cool off.
Anyone else experienced this?
The A/C had been on 70deg F on AUTO. I pushed the front windshield defrost button, the fan went to full and the air coming out, hitting the windshield and blowing on my face was uncomfortably hot. Turning down the temperature control to 64 didn't change the air temperature. Only when I turned the temp to LO did the air cool off.
Anyone else experienced this?
10-23-2003, 05:16 PM
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The defroster will go to the highest heat and fan setting righ off the batt. The Mercedes do the same thing. It is for a quick defrost or de-fog of the windows. It's programed that way.
10-23-2003, 06:14 PM
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dfar,
the strange thing is that the temp was set to 70, although the fan was at high.
from what you described, I would have expected to see the temp at max as well.
the strange thing is that the temp was set to 70, although the fan was at high.
from what you described, I would have expected to see the temp at max as well.
10-23-2003, 09:11 PM
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The windshield is a manual heat button not registered on the auto heat display.
Another undisplayed function is the AC comes on in economy mode (over rides it) to dehumidify the air, even when you set the dial to bring heat in. Unnerving to get the AC when freezing.
Another undisplayed function is the AC comes on in economy mode (over rides it) to dehumidify the air, even when you set the dial to bring heat in. Unnerving to get the AC when freezing.
10-25-2003, 11:54 AM
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Mo matter what the temp is set to it will override to full heat and kick in the compressor as Torags stated. Even in the summer when it rains and the windows fog up from not having any climate control on. The defroster is ment to be used temporary and not on all the time as in U.S. cars.
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10-25-2003, 01:35 PM
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Originally posted by ltc
Torags,
Where did you find this? I have gone thru the manual but can't find anything on it.
Thanks
Torags,
Where did you find this? I have gone thru the manual but can't find anything on it.
Thanks
My service rep confirmed it. I haven't seen anything written yet.
I'll bet it's all part of the drive by wirer conspiracy. Electronics taking away the driving responsibilities from the dummie operator.
10-25-2003, 02:03 PM
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Originally posted by Torags
Another undisplayed function is the AC comes on in economy mode (over rides it) to dehumidify the air, even when you set the dial to bring heat in. Unnerving to get the AC when freezing.
Another undisplayed function is the AC comes on in economy mode (over rides it) to dehumidify the air, even when you set the dial to bring heat in. Unnerving to get the AC when freezing.
10-25-2003, 05:15 PM
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There was a flaming thread on the Toureg Forum about misted windows being a danger, etc., etc...
Peppers don't seem to have the problem (maybe because of the AC override).
Peppers don't seem to have the problem (maybe because of the AC override).
10-25-2003, 10:14 PM
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how long does it ususally take to defrost? mine is usually done within 30 seconds, and doesn't the windshield frost up when the temp outside is cold most of the time?
10-26-2003, 01:44 AM
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Wow....
First, Porsche's windshield defrost/defog/demist function is doing exactly what it should. The designers of the climate control system have no way of knowing, no sensors, no automatic detection system, etc, just how serious the matter is. So the very best thing for them to do is design the system to apply MAX HEAT & MAX BLOWER (and typically and over-ride into "fresh" inlet airflow), this on the assumption that either the inside or outside of the windshield is fully misted over.
IT HAPPENS!
You're lucky you're not driving a Lexus or Toyota, or any vehicle with a climate control design by NipponDenso or Denso USA. It's taken over ten years for Lexus/Toyota to figure out that the A/C CANNOT be used for dehumidifying incoming airflow below or near freezing outside temperatures. In reality the ability to use A/C to help defog the inside of the windshield declines dramatically as the outside temperature declines below about 50F.
Most modern day systems will automatically disable the A/C compressor clutch once the outside temperature declines to ~35F, some even disable at about 47F.
Denso turns theirs off at 35F but still doesn't have the sense to know to use HEAT as an alternative. Just not reading the 2004 technical specs and Denso may have corrected this after ten years.
Having said all of that be care of you Porsche during the summer months when it hot and humid. Both my 99 C2 and now my 01 C4 will (inadvertantly) CHILL the windshield during cooling mode. Once the cabin temperature is very near or at the setpoint the system will switch modes, invisible to the operator, and open the windshield defrost/defog/demist ducts to outlet cooling airflow.
Anyone want to join a class action lawsuit.
Sorry, not serious.
Do a search for "fogging" over on the 996 board.
First, Porsche's windshield defrost/defog/demist function is doing exactly what it should. The designers of the climate control system have no way of knowing, no sensors, no automatic detection system, etc, just how serious the matter is. So the very best thing for them to do is design the system to apply MAX HEAT & MAX BLOWER (and typically and over-ride into "fresh" inlet airflow), this on the assumption that either the inside or outside of the windshield is fully misted over.
IT HAPPENS!
You're lucky you're not driving a Lexus or Toyota, or any vehicle with a climate control design by NipponDenso or Denso USA. It's taken over ten years for Lexus/Toyota to figure out that the A/C CANNOT be used for dehumidifying incoming airflow below or near freezing outside temperatures. In reality the ability to use A/C to help defog the inside of the windshield declines dramatically as the outside temperature declines below about 50F.
Most modern day systems will automatically disable the A/C compressor clutch once the outside temperature declines to ~35F, some even disable at about 47F.
Denso turns theirs off at 35F but still doesn't have the sense to know to use HEAT as an alternative. Just not reading the 2004 technical specs and Denso may have corrected this after ten years.
Having said all of that be care of you Porsche during the summer months when it hot and humid. Both my 99 C2 and now my 01 C4 will (inadvertantly) CHILL the windshield during cooling mode. Once the cabin temperature is very near or at the setpoint the system will switch modes, invisible to the operator, and open the windshield defrost/defog/demist ducts to outlet cooling airflow.
Anyone want to join a class action lawsuit.
Sorry, not serious.
Do a search for "fogging" over on the 996 board.
2004, car, cayenne, defog, deforst, defrost, defroster, defrosters, defrosting, defroze, fan, front, porsche, shutting, summer, temp, temperature, windsheild, windshield, winshield
