Hot air from windshield screens while cold at vent

[Sean Roth]

Have any of you had this issue where you turn heat on and hot air comes from the upper dash screens near windshield but the face vents have cold ambient air?



SF Roth

[Hasbeen]

I haven't had that one Sean, but have had some strange things happen with the ventilation system.

Have a look at the sides of the unit under the dash. I had an ongoing problem with the control wire link fittings, dropping off the splines at the side of the unit. They then did nothing of course when the controls were moved.

If they are off, be careful putting them back on. Although a couple were falling off every 10,000 miles or so, they were very hard to get off under there, if you put them back on in the wrong place.

Guess how I know that. [:I]

This could be your problem, if a PO has put then on out of place.

Hasbeen

[stevie_a]

<font color="teal"><b>I think the face vents are cold air only</b></font id="teal">

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<font size="4"><font color="green"><i>If it's not broke don't fix it.</i></font id="green"></font id="size4">

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[andyf]

That is correct, as Stevie says the face vents are fresh air only.


1980 Persian Aqua DHC

[TR Tony]

Yes, that is definitely correct, center vents fresh air only, side vents will give warm air to demist the side windows. Set the VENT slide to off & this should stop the fresh air from the center vents if the heater box connections & flaps are correctly set.

Tony

<font size="1">1981 TR7 FHC Cavalry Blue
1980 TR7V8 DHC Jaguar Regency Red - sadly sold!
1977 TR8 FHC EFI Factory development car Inca Yellow</font id="size1">

[jeffremj]

<blockquote id="quote"><font size="1" face="Century Gothic, Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by TR Tony</i>

Yes, that is definitely correct, center vents fresh air only, side vents will give warm air to demist the side windows. <hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">I have never, ever had hot air from the side vents - always cold. Had one car from 3 years old (the car not me [:)]), so would imagine that was how it was designed.

[FI Spyder]

I think there is a difference between how the A/C heater and the standard heater works. For A/c system, cold air only on side vents. Warm air from the centre vents when on hot. There is an extra position on the fan speed that is called Max were outside air is cut off and only interior air is recirculated for maximum cooling when using the A/C.

- - -TR7 Spider - - - 1978 Spitfire- - - - 1976 Spitfire - - 1988 Tercel 4X4 - Kali on Integra - 1991 Integra - Yellow TCT

[TR Tony]

<blockquote id="quote"><font size="1" face="Century Gothic, Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by jeffremj</i>

[quote]<i>Originally posted by TR Tony</i>

Yes, that is definitely correct, center vents fresh air only, side vents will give warm air to demist the side windows. <hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">I have never, ever had hot air from the side vents - always cold. Had one car from 3 years old (the car not me [:)]), so would imagine that was how it was designed.
<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote"> Yup, you are right about that, side vents are unheated air, with their own little control wheel to regulate the flow. Center vents are also unheated but controlled from the heater panel lever.

Tony

<font size="1">1981 TR7 FHC Cavalry Blue
1980 TR7V8 DHC Jaguar Regency Red - sadly sold!
1977 TR8 FHC EFI Factory development car Inca Yellow</font id="size1">