I have a 98 Z28 and the A/C is only blowing out the defrost and bottom. I've been told it's a vacuum line. Where would I find the vacuum lines for the A/C?

 

so even when you put it on defrost it still stays on split level.

 

theres a vacuum line in the engine compartment. maybe its damaged or unhooked. should be on the passenger side and go into a wire harness. that line feeds into the heater controls under the dash. from there the lines go to the control valves.

 

Yes. No matter what i put it on it blows out defrost and feet.

 

check the vacuum line under the hood. it hooks up to the passenger side of the intake manifold and should go into the passenger compartment wiring harness. do you hear a sucking noise inside the car when engine is running?

 

No. I don't hear any sucking noise inside car.

 

check the vacuum hose under the hood and make sure its hooked up and not damaged. should be the only one that goes away from the engine.

 

I guess I'm looking at the right line craby. Look good to me but I'm probably looking at the wrong ones.

 

does it go into a wiring harness or into the firewall? should go to the passenger side of the intake manifold. have a look at this 1998 HVAC hoses/lines, how to route and connect? - LS1TECH

 

There is a small t-fitting between the a/c evaporator unit and the pcm at the firewall. See if it is broken or if any of the three small hoses are disconnected. The photo is for a 95, but the 98 fitting is the same and in the same location.

http://shbox.com/1/vac_check_valve.jpg