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#103938 - 04/28/09 03:47 PM A/C out of defrost and nothing else
nyjets91 Offline
Member
Registered: 04/24/09
Posts: 469
Loc: Wallingford/Hartford, CT
Now that I've got an accurate reading on the outside temperatures, I need help with another HVAC problem. My heat and A/C both blow hot and cold respectively, but i'm noticing that it's only coming out of the defroster vent(s) on the very top of the dash against the windshield. I'm told that there could be a vacuum line messed up that it not activating the servo or whatever controls the doors that change the airflow direction. Where would I look for this? Any help would be hugely appreciated because it sucks when the A/C is on but you can barely feel it because it's coming out of the farthest possible vents.
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'99 Forest Green Coupe GT - Stock except for red overlays on logos and Taylor 8mm Spiro Pros
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#103939 - 04/28/09 03:50 PM Re: A/C out of defrost and nothing else
nyjets91 Offline
Member
Registered: 04/24/09
Posts: 469
Loc: Wallingford/Hartford, CT
It's the CJ2 unit, the fully digital 2-zone one, if that's important.
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'99 Forest Green Coupe GT - Stock except for red overlays on logos and Taylor 8mm Spiro Pros
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#103940 - 04/28/09 04:15 PM Re: A/C out of defrost and nothing else
r.s.hutchinson Offline
Member
Registered: 01/01/08
Posts: 3900
Loc: Ontario, Canada
Yes, it's a vacuum modulated unit and is a HUGE PITA to change if it is in fact the unit.
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00 Turbo GTP - 97 GTP - 03 GSXR600
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#103941 - 04/28/09 04:22 PM Re: A/C out of defrost and nothing else
nyjets91 Offline
Member
Registered: 04/24/09
Posts: 469
Loc: Wallingford/Hartford, CT
but where is it and where is the vacuum line that goes to it so I can at least check that first?
_________________________
'99 Forest Green Coupe GT - Stock except for red overlays on logos and Taylor 8mm Spiro Pros
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#103942 - 04/28/09 04:23 PM Re: A/C out of defrost and nothing else
r.s.hutchinson Offline
Member
Registered: 01/01/08
Posts: 3900
Loc: Ontario, Canada
i'm still looking to find a picture for you.

My friends g/f GTP is having this same issue and I don't think they are fixing it just because of the location...
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00 Turbo GTP - 97 GTP - 03 GSXR600
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#103943 - 04/28/09 04:27 PM Re: A/C out of defrost and nothing else
Blackarrow98GP Offline
Member
Registered: 06/29/06
Posts: 3618
Loc: CT, U.S.A
There's a vacuum/electric solenoid under the dash on the passenger side, to the right of the blower motor case. Check the vacuum line there for leaks.
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#103944 - 04/28/09 04:29 PM Re: A/C out of defrost and nothing else
nyjets91 Offline
Member
Registered: 04/24/09
Posts: 469
Loc: Wallingford/Hartford, CT
do i have to take out the glove box or anything? or just stick my head under there?
_________________________
'99 Forest Green Coupe GT - Stock except for red overlays on logos and Taylor 8mm Spiro Pros
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#103945 - 04/28/09 04:36 PM Re: A/C out of defrost and nothing else
Blackarrow98GP Offline
Member
Registered: 06/29/06
Posts: 3618
Loc: CT, U.S.A
Take off the gray panel below the glove box, it's held on with push pins.
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#103946 - 04/28/09 04:37 PM Re: A/C out of defrost and nothing else
nyjets91 Offline
Member
Registered: 04/24/09
Posts: 469
Loc: Wallingford/Hartford, CT
ok, im gonna go outside and do that now
_________________________
'99 Forest Green Coupe GT - Stock except for red overlays on logos and Taylor 8mm Spiro Pros
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#103947 - 04/28/09 06:51 PM Re: A/C out of defrost and nothing else
GrindingNemo Offline
Member
Registered: 11/23/08
Posts: 255
Loc: Missoula MT
I would check the ignition switch. The contacts inside mine got covered in carbon and caused basically the same thing to happen.
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#103948 - 04/28/09 07:06 PM Re: A/C out of defrost and nothing else
nyjets91 Offline
Member
Registered: 04/24/09
Posts: 469
Loc: Wallingford/Hartford, CT
Blackarrow, I didn't see any leaks in the vacuum lines under the dash. Am gonna look again later to double check.

Nemo, not sure how it would be the ignition switch when everything else that runs off of it is fine. Also, the A/C still blows cold air, but it's coming out of the wrong vents at times.

An update though, It seems that on the setting where the arrow points at the man's face on the CJ2 unit, about 60ish% of the air comes out of those (correct) vents, but the rest splits between the defroster vents and the feet. On any other setting however, it comes almost entirely out of the defrost vents, with a trickle coming out at the feet. Even on the one where it's supposed to be half feet and half middle vents, most of the air comes out at the defrost. Anyone got any other ideas as to why this would occur?

As always, thanks in advance for any help.
_________________________
'99 Forest Green Coupe GT - Stock except for red overlays on logos and Taylor 8mm Spiro Pros
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#103949 - 05/04/09 06:56 PM Re: A/C out of defrost and nothing else
nyjets91 Offline
Member
Registered: 04/24/09
Posts: 469
Loc: Wallingford/Hartford, CT
So I'm trying to bump this and get any other answers i can get. any help is appreciated.

From my description in my previous post, is it possible that something is blocking the doors inside the dash from moving? Also, if someone could point me to a link on how to remove part of the dash and where to look to find this possible obstruction, that would be great.

Once again, any help at all would be appreciated.
_________________________
'99 Forest Green Coupe GT - Stock except for red overlays on logos and Taylor 8mm Spiro Pros
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#103950 - 05/04/09 07:17 PM Re: A/C out of defrost and nothing else
Blackarrow98GP Offline
Member
Registered: 06/29/06
Posts: 3618
Loc: CT, U.S.A
Have you checked the climate control unit for stored codes? Click this link for more info: http://www.grandprix.net/ubb/ultimatebb.php?ubb=get_topic;f=1;t=004227;p=1#000009 (Scroll down)
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#103951 - 05/04/09 07:51 PM Re: A/C out of defrost and nothing else
nyjets91 Offline
Member
Registered: 04/24/09
Posts: 469
Loc: Wallingford/Hartford, CT
I tried this, the only code was 104 (historic ambient sensor circuit open). I know this is because i has ran the car briefly with no sensor plugged in before I got the new one. It's not showing any other codes.
_________________________
'99 Forest Green Coupe GT - Stock except for red overlays on logos and Taylor 8mm Spiro Pros
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#103952 - 05/04/09 08:19 PM Re: A/C out of defrost and nothing else
Blackarrow98GP Offline
Member
Registered: 06/29/06
Posts: 3618
Loc: CT, U.S.A
If you can't find any vacuum leaks, you can try cleaning the ignition switch first. If that doesn't fix it, it's time to get out the digital multimeter, and start checking the wiring harness between the solenoid and climate control unit.
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