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MikeDanger

Joined: 21 Nov 2002 Posts: 774 Location: Denver
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Posted: Wed Jan 29, 2014 7:55 am Post subject: vent Fan runs?/Heat question |
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is the vent fan supposed to run no matter what?? Its always on when I turn the key on, since I dont really need it when its 32F.
on that same note, I dont seems to be feeling much heat, If the temp gauge is in the middle the car should be warm enough to provide heat right?
also is there a guide for the function of the climate control settings? They arent very clear except for "all right for defrost" _________________ It was either this or a giant box of legos |
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GeorgeV

Joined: 14 Mar 2010 Posts: 306 Location: Brisbane, Australia
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Posted: Wed Jan 29, 2014 9:54 pm Post subject: Re: vent Fan runs?/Heat question |
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| MikeDanger wrote: | | is the vent fan supposed to run no matter what?? Its always on when I turn the key on, since I dont really need it when its 32F. |
Yes, that's how it's wired from the factory. _________________ 1981 932 with mods:
http://www.924board.org/viewtopic.php?t=37921 |
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brian19600

Joined: 28 Oct 2013 Posts: 375 Location: NJ/CT
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Posted: Thu Jan 30, 2014 12:37 am Post subject: |
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Summary from my '78 owners manual:
Upper lever:
lever to left-air ducts closed with fan at low speed
lever to center-air ducts open with fan at low speed
lever to stop 1-medium fan speed
lever to stop 2-high fan speed
Center lever:
lever to left - heater off
lever to right - heater on
adjust to any intermediate position for desired heat range
Lower lever
lever to left - air flow to footwells
lever to right - air flow to windshield and side window vents
It also mentions that the center dash vents are for fresh air ventilation only.
brian _________________ 78 924 |
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Harm

Joined: 02 Apr 2009 Posts: 1376 Location: Holland
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Posted: Thu Jan 30, 2014 2:39 am Post subject: Re: vent Fan runs?/Heat question |
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| ^IIRC the '78 and '80 HVAC are of a different type… |
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MikeDanger

Joined: 21 Nov 2002 Posts: 774 Location: Denver
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Posted: Thu Jan 30, 2014 5:32 am Post subject: Re: vent Fan runs?/Heat question |
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| Harm wrote: | | ^IIRC the '78 and '80 HVAC are of a different type… |
Yeah I hope so, I need all the heat I can get! _________________ It was either this or a giant box of legos |
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fiat22turbo

Joined: 18 Jan 2006 Posts: 4040 Location: Portland, OR
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Posted: Thu Jan 30, 2014 5:36 am Post subject: |
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Don't hold your breath. It wasn't until the late 924S and 944 before they got the system to work somewhat decently, mostly due to the change in the type of fan used among other changes. _________________ Stefan
1979 924 Carrera GTS (clone-ish)
1988 944 Turbo S (Silver Rose) |
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MikeDanger

Joined: 21 Nov 2002 Posts: 774 Location: Denver
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Posted: Thu Jan 30, 2014 5:45 am Post subject: |
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ok well how to I get heat to come through the center vents?? _________________ It was either this or a giant box of legos |
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ideola

Joined: 01 Oct 2004 Posts: 15550 Location: Spring Lake MI
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Posted: Thu Jan 30, 2014 6:36 am Post subject: |
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| MikeDanger wrote: | | ok well how to I get heat to come through the center vents?? |
You don't. Hot air only goes to the footwell or the side/windshield vents.
With a normal range thermostat and fan switch, the 924 usually produces plenty of heat for the cabin. The fan, however, is pretty weak and does not do a very good job of defrosting the windshield regardless of how hot the air is.
If you're not getting sufficient cabin heat, it can be due to a multitude of issues, including:
- previous owner installed a cooler t-stat/fan switch combo for lower running temps in summer
- previous owner screwed up the t-stat/fan switch combo (they need to be a matched pair)
- heater control valve is stuck closed
- bowden cable operating the heater control valve is broken or disconnected on one end or the other, and the heater control valve is closed
- heater core has failed (usually resulting in coolant leaking into the passenger footwell)
- heater core is plugged
- heater hoses are bypassed or plugged or leaking _________________ erstwhile owner of just about every 924 variant ever made |
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larchie
Joined: 19 Jun 2003 Posts: 297
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Posted: Thu Jan 30, 2014 9:14 am Post subject: |
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ideola wrote:
| Quote: | | - heater control valve is stuck closed |
Also if your heater controls have a broken plastic web, Porsche made available a steel bracket replacement PN 477 819 057 which goes between the plastic housing and the spring clip PN 823 819 679 holding the cable.
Another suggestion is to replace the thermostat with a winter one PN 059 121 113A which opens at about 190 degrees F, if you run the car only in below-freezing weather and mostly on highways. (The standard thermostat opens at around 176 degrees F.) |
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!tom

Joined: 28 Aug 2006 Posts: 1941 Location: Victoria, BC Canada
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Posted: Thu Jan 30, 2014 4:06 pm Post subject: |
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| ideola wrote: | Hot air only goes to the footwell or the side/windshield vents.
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Not on mine. As others have said, there's many different configurations.
Mine has "hot" air for feet or windshield. Side and centre vents bypass the heater core completely.
Your model may vary, depending on the A/C variant installed, year, etc. _________________ 78 924 NA
5-lug |
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Rasta Monsta

Joined: 12 Jul 2006 Posts: 11733 Location: PacNW
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Posted: Thu Jan 30, 2014 4:18 pm Post subject: |
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| ideola wrote: | If you're not getting sufficient cabin heat, it can be due to a multitude of issues, including:
- previous owner installed a cooler t-stat/fan switch combo for lower running temps in summer
- previous owner screwed up the t-stat/fan switch combo (they need to be a matched pair)
- heater control valve is stuck closed
- bowden cable operating the heater control valve is broken or disconnected on one end or the other, and the heater control valve is closed
- heater core has failed (usually resulting in coolant leaking into the passenger footwell)
- heater core is plugged
- heater hoses are bypassed or plugged or leaking |
Add to this busted control head. _________________ Toofah King Bad
- WeiBe (1987 924S 2.5t) - 931 S3
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MikeDanger

Joined: 21 Nov 2002 Posts: 774 Location: Denver
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Posted: Thu Jan 30, 2014 5:09 pm Post subject: |
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| !tom wrote: | | ideola wrote: | Hot air only goes to the footwell or the side/windshield vents.
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Not on mine. As others have said, there's many different configurations.
Mine has "hot" air for feet or windshield. Side and centre vents bypass the heater core completely.
Your model may vary, depending on the A/C variant installed, year, etc. |
well that sucks. I didnt pay attention to if I was getting heat upper and lower, will check next time. _________________ It was either this or a giant box of legos |
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