need help with a/c

[mobileone]

Whenever I turn on the a/c no matter which selection it is it will only blow a/c through the floor vents and the dashboard. Anyone know whats wrong?

[2001NBMZ28]

Look for a loose/disconnected vacuum line behind the intake first - think that's the default setting.

[mobileone]

Can you describe exactly which lines they might be? Thanks

[2001NBMZ28]

Here's another possibility www.ls1.com/forums/showthread.php?t=22275 If that's not it follow the vacuum lines that connect to the valve.

[Frankthetank]

yea its a line on the back of the intake manifold....the air is all vacuum controlled. I had the same problem....it might have come disconnected or if u have done any mods to it lately....it may have been just not put back on after manifold was takin off

[96z28]

I had this happen on my old 96z28 and yes there was a vacuum leak. The vacuum line runs on the passanger side of the engine compartment. I know that a guy by the name shoebox had a site that showed how to find it and fix it.

[mobileone]

Do you have a link to that site? I haven't had time to take a look at it yet.

[2001NBMZ28]

Shoebox's site is http://shbox.com LT1's are probably a little different though.

[SSpdDmon]

If you reach behind the intake from the passenger side, there is a little black hose about the diameter of a drinking straw. It slides onto a connector hooked to the back of the intake. You really can't see it...you'll have to feel around. Just watch out for the sharp S.O.B.s underneath the cowl.


(Assuming you have an LS1)

[mobileone]

Yes I have an LS1. Ok I was feeling around and looking at my old intake to familiarize what I was feeling.Ok looking at my original LS1 intake there should be three things hooked up to it, looks like the map sensor and below that one line that goes to the passenger side which looks like the size of a sraw and one going to the driver side which looks to be thicker. Well where there is suppose to be something hooked up going to the pasenger side there was no line hooked up. So I'm assuming thats the problem. Where would the other end of this straw like hose be hooked up to?

[SSpdDmon]

Your HVAC system. If I remember correctly, it feeds from somewhere behind the PCM. If you can't see it from up top, get a flashlight and slide on under that bitch. Sux, but at least you know the problem now.

[mobileone]

i finally fixed it. I found the little hose from the hvac system which was sticking out from a bunch of wires covered in that black plastic. It was a bitch getting my hand all the way back there and plugging it in. I had to sit on top of the lid to reach back there. The little hose is a bit thinner than a straw I would say. But thank you all for helping me out, now I can drive my car during the day without being soaked in sweat.

[2001NBMZ28]

Cool, glad you found it.