air only blows out the defrost vent

1999 OLDSMOBILE 88
114 MILES • 3.8L • 6 CYL • FWD • AUTOMATIC
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RONALD FRANKLIN
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I followed your advice on replacing the A/C compressor. it is working great. I have a problem now, the cold air only blows out the defrost vent no matter what I set the control on. any help would be greatly appreciated. thanks again
Jul 15, 2017 at 2:46 PM
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STEVE W.
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This is the anniversary edition correct? Does it have the automatic or manual control system. They are slightly different. But the most common issue is a broken vacuum line or bad vacuum control from the control head.
If it is a bad vacuum actuator the heater box has to come out to get to it. That means the instrument panel has to come out, the AC and heater system has to be drained and discharged, then you can get to the controls that are on top of the HVAC module behind the dash.
It is a real bear to do so I hope the issue is a line.
Jul 15, 2017 at 3:32 PM
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RONALD FRANKLIN
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Thanks Steve. i removed the glove-box and found a white plastic arm that was broken looks like it was connected to a small metal rod with ridges on the left and a plastic lever on the right and yes it is an anniversary edition.
Jul 15, 2017 at 3:48 PM
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STRAILER
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Hello,

Yep that is the controller that adjusts the temperature and air flow or the system. Use must fix the arm or replace the unit.

Please let us know what happens.

Cheers, Ken
Jul 17, 2017 at 11:42 AM
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STEVE W.
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As Ken said, that is a linkage arm. The ridges are basically to lock the plastic on. Set the temperature to full cold, now move the arm until you get full cold air and the door stops. That is the point you clip the two parts together. If they have fallen apart (usually because of the age of the plastic) you can use a couple small zip ties or even thin wire to hold them together.
Jul 17, 2017 at 12:50 PM
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RONALD FRANKLIN
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Sorry to keep bothering y'all but the plastic box on the right does not want to move freely it acts like something is keeping it from moving thanks guys
Jul 18, 2017 at 4:52 PM
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STRAILER
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Can you please take a picture and upload it so we can see what you are talking about?
Jul 19, 2017 at 10:53 AM