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HVAC Programmer issue? AC only blows through defrost vents

Old 01-26-2008, 06:46 PM
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Default HVAC Programmer issue? AC only blows through defrost vents

Hi,
I am new to this loop and was thrilled to find it! I am a little frustrated with my 1998 Bonneville SLE. The air conditioning blows strong and cold, but only out of the upper defroster vents. I tried testing the fuse for the ac programmer with a light tester and it was fine. I replaced the little vacuum hoses under the hood that comes from the intake and continues to the thick wire loom traveling into the ac outer firewall box. There is a little Y connector for the vacuum hose at the end nearest the firewall. I only replaced the hoses up to there. All the rest seem to be plastic and are good. I also went to the salvage yard and picked up a second ac dash controller with the buttons and display on it. That did not work either. Please help!!! What else can I do to fix this issue?

Email me at 6781camaro@tampabay.rr.com

I love the car and drives like a dream, but I must get this air fixed pronto!

Thanks!

Todd[/list]
Old 01-26-2008, 09:54 PM
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does the heat switch between vents fine? it could just be the ****
EDIT: saw you replaced that from the junk yard. nvm
Old 01-27-2008, 08:07 AM
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Default Ac only coming out of the upper defroster vents

As I mentioned in my original post, I have the electronic dash ac controller--no *****. I already replaced that though. Any other suggestions?
Old 01-27-2008, 08:12 AM
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Default BC System...

I looked up the ac programmer and it was $422.76!!! WOW! Why?

Where can I get it any cheaper?
Old 01-27-2008, 08:48 AM
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You might want to check the vac connections at the HVAC box. It sounds as if it isn't getting vaccuum to enable switching.
Old 01-27-2008, 09:02 AM
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Default Ac only coming out of the upper defroster vents

thanks, I will check that out today.

Todd
Old 01-27-2008, 01:02 PM
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Default programmer box connections

In order to remove those vacuum hoses connected to the programmer box, do I just undo that little nut located in the center of the hoses? I also noticed that at about the 2 o'clock position, there is an open vacuum port on the programmer where that circle of hoses attaches. Is that correct or am I missing a hose there? Seem strange to have an open port. While the was running I did press my finger over that open port and there wasn't any vacuum.

Thanks
Todd
Old 01-27-2008, 01:11 PM
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That open port is a vent for opposing airflow. And yes, undo that little nut. I am almost certain that your problem lies in the lack of vaccuum to the HVAC box. Defroster is the default position when there isn't any vac.
Old 01-27-2008, 01:25 PM
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Default vacuum leak

Thanks for the help. I sincerely appreciate it. I will check that out later today.

I did already check the vacuum source under the hood, where it connects to the manifold and then into the Y-connector located in that thick wire loom. I know the vacuum is still good up to that point. I will have to check the line that actually passes through the firewall and connects to that single lead hose located at that cluster of hoses on the programmer.

Thanks again. Wish me luck... It'* so hard to get to with a bad back!

Todd
Old 01-28-2008, 12:02 PM
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99% sure your nipples are plugged/collapsed at that vacuum connector underneath the dash.

Should be under $2.00 for vacuum line to make the connection from NAPA. Here is the procedure to fix:

http://www.bonnevilleclub.com/forum/...ghlight=nipple

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