A/C Not Blowing Through Top Vents

[Stovall98]

I have a 98 Camaro and the air conditoner only blows from the floor vents. The air is still cold but will not blow from top vents. Has anyone had this problem?? How do you fix it. Vacume Hoses?? or pump?

[Wicked 3800 V6]

Happens now and then. Give it a few days, while trying the switch now and then. Might un-stick itself.
If not, I dunno.
-Rob

[Ex-5.0]

Similar problem on a friend's 2000 was broken vacuum check valve -- caused vacuum leak & loss of vacuum to AC controls. Default w/ no vacuum puts air to floor & defroster vent only.

Located pass side under hood near front of AC evap core box.

Original check valve made out of cheap black plastic that disintegrated.

New valve ($1.50 at dealer) was different plastic (yellow/white body), same as my 2002, looks stronger than old one.

[need4speed]

or broken/cracked vacuum line elsewhere.

[93v6firebird]

vacuum leak is the most likely.
However the diverter behind the dash could need oiling... check that if you find all vacuum lines in good shape.

[Stovall98]

Thanks guys i'll look into it and get back with yall.

[xjarayax]

I had the valve go out on me too, but maybe it was a different one as mine was like 16 bucks from the dealership.

[HotWheelz]

Anyone have a clue as to whether a '94 might have the same valve as a '98? I've been having the same problem with mine, but I wasn't able to locate the plastic valve you guys were talking about.

[Ted]

I kinda have a similar problem but the opposite. I found my vacuum lines that run by the PCM off, and my A/C has never worked since I got the car. Me and a friend replaced all the vacuum hoses to where they go. (We looked off my friends T/A) The problem is there isn't enough vacuum to kick open the vents that blow towards you, it only blows out the top and bottom. I think I have a leak somewhere back there because I held my thumb over the vacuum hose and you can hear it leak a little. By the time I get it fixed, summer will be over, lol.

[Salvader]

Had the same problem, turns out it was a bended vacum line, on the passengers side under the hood. But still have the problem of hot air in fron the bottom when the ac is off.

[modulation]

Re: A/C Not Blowing Through Top Vents

Ex-5.0, you solution solved my problem of the air only coming out heater/defroster vents with your suggestion of a 3 way check valve.

THANK YOU! You are so awesome, I was about to take it into a shop before I read your suggestion. Wonder how much they would have charged me to replace the hood and replace a <$5 part.

[andrew.brandon]

Re: A/C Not Blowing Through Top Vents

hmmm been having the same problem for about a year. I will have to check this out. how much was the valve modulation? and did you get it from a regular auto parts store?

[modulation]

Re: A/C Not Blowing Through Top Vents

I got mine from NAPA online. I have a 1994 year camaro, and the part is located right next to the computer, close to the firewall where hood pnematic arm mounts.

Item: Check Valve - Universal One Way Vacuum
Product Number: BK 7301348
Quantity: 1
Price: 2.69
Core Price: 0.00
Total Credit: 2.69

[pcgame4life]

Re: A/C Not Blowing Through Top Vents

Can someone give me a picture as to what needs to be replaced? I have the same problem, when my A/C is set on the vent and floor setting, it sometimes blows through vents, but on any other setting (including "MAX and A/C") it only comes through defrost and floor.

[Fred]

Re: A/C Not Blowing Through Top Vents

My driver side floor vent won't blow cold air or heat. Is it the same problem?