Air and Heat comming from defrost vents

[NY87GN]

Looking for some guidance on my 87 GN. When I put my ac on max the air comes from the defrost vents. A friend of mine mentioned its a vacuum line some where. Can someone point me in the right direction...im a novice, so please provide as much detail as possible..
Thank you in advance for your help!!

 

[69RSCLONE]

Check the vacuum switching valve at the back of the control panel. It's a round black valve with a bunch of colored hoses going to it. If you here vacuum leaking from it it's bad. Once it leaks it defaults to defogger and floor.

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[tufbuick]

Also check Vacuum lines at the throttle body area L&R side. Mine had same problem and I found a vac line that shook loose.

 

[NY87GN]

Sorry for asking do you have a picture of the vacuum switching valve at the back of the control panel. Thanks again!!

 

[69RSCLONE]

Sorry, I don't. I just had mine apart 2 weeks ago, but no pictures. There is a little white plastic clip in the middle that holds it together. Mine had broken and letting it leak vacuum. I just used a metal screw that was left over from when my pool was installed, screwed right in the middle and tightened until it had good tension on the metal spring.

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[69RSCLONE]

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[69RSCLONE]

Found some on Google

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[NY87GN]

Thank you all !!!