mbella2000

Hi all

I have a 2000 vette with 51k. Recently in the past month when I put my a/c on, it blows out half as hard through the front vents all of a sudden and it blows out about 25% through the defroster even though I have the setting on vents only. Can anyone tell me what the issue may be besides a vacuum hose behind the vent console? Even on full it blows only about 60% of the normal force it blows out..

Thanks!

cdkcorvette7

Any HVAC codes present in the DIC?

Why do you think it isn't a broken vacuum line? If you've removed your intake manifold recently the small line off the back of it (very easy to break) could have snapped and caused this. That line also runs underneath the batter compartment and it's relatively common for acid drip to damage that line and cause the condition you're having...

Are you sure it's only blowing out of the defroster and not ALL of the vents? Put your hand under the floor vents and check...

mbella2000

Hi thanks for the reply. I stated anything but behind the vent console because I had it out last week when I had to replace my hazard dash button switch and the vent was doing this before my hazard switch replacement.. There are no codes present. My engine has never been worked on and nothing has been removed from the engine compartment inc a manifold or even a hose etc.. Everything is still original minus an a/c belt a year ago and oil change. My battery is new though and is not dripping anything at all. Everything looks nice and clean. PS it is blowing out all the vents including the defroster but for some reason the middle vent is at about 60% less than the side vents and the defroster one has cold a/c blowing out it at about 25% or so all the time even when I have the settings on front vents only... Don't know what it could be ....

cdkcorvette7

Check the line that runs from the back of the manifold down below the battery and to a valve behind the rf wheel well... Pull the line out of the valve and put your finger on it to check for suction...

Matti

I just fixed this issue in my 2000 vette its gotta be something with your vacuum lines maybe the line under your dash got messed up when you took your dash out or something. I'd check there first then go through the rest of the lines. This should help
http://forums.corvetteforum.com/c5-g...with-pics.html

mbella2000

Thanks for the reply

I looked down the battery and no vacuum lines. All I saw and felt were electrical connections. I turned both wheels looking for a vacuum line at the wheel well as you stated and saw nothing as well

cdkcorvette7

There are two vacuum lines off of the back of the intake manifold. The smaller of the two controls the hvac vents. It runs down the passenger side of the engine bay beneath the battery cover and terminates at a valve behind the wheel well. You have to unscrew the bolts holding the plastic inner fender liner on and pull it aside to see the valve. Part of the line is inside a wire loom so it can be a little difficult to locate...

Pics and directions are here: http://forums.corvetteforum.com/c5-g...with-pics.html

Bill Curlee has some better pics. If he sees this thread he might post them for you. Based on the symptoms you have it is almost definitely a vacuum issue.

BigGun

The lines are there, you obviously don't know what they look like. They are thin hard lines (nylon i think) not the big rubber lines commonly used on the rest of the engine. They are often mistaken for electrical wires if you don't know what they look like. Pull the battery and you can get a better look.