I have a 1996 Collectors Edition LT4 with 130,000+ miles on it and it runs very strong. However, the Climate control system has never worked well at all. I can't get the airflow to change from coming out the de-fogg outlets near the base of the windsheild. the AC works, cools and heater heats. But I cant change the airflow to the floor for heat on my toes or to the dash for AC in the summer.

Help?

that sounds like a vacuum problem.

There are a number of hoses that come off the right side of the intake (under the fuel rail covers). I would check to be sure the vacuum or the connector isn't broken.

If it ain't that... you will have to start digging.

Do you have the Helm factory service manual? If not, get it.

Within the FSM, there are instructions on how to get codes out of the climate control programmer. Also, any lights flashing on the climate controller? The auto light will flicker if there are problems, but you can still learn things about the status of the system from checking the codes and status indicators.

I have the FSM for my 1992, but I don't know if the codes or procedures stayed the same.

If I was a betting man, I would check for vacuum related problems.

Check the vacuum check valve under the right fuel rail cover. these bread real regular, if your cruise control also dosn't work, it's a for sure thing.

I agree with 94hillbilly. I just fixed my 94 by replacing the vacuum check valve underneath the right fuel rail cover. It had pretty well disintegrated and was leaking badly. Good news it was less than $10 at Chevy dealer.

I know its a different vehicle, but in my Ford Ranger, the vacuum "ball" had a hose come off and it did the exact same thing. Check the hoses around it and see what happens.

I am new to the forum, great job C4 guru. I alsohave a 96 CE with the same problem. I have the manulas so I will begin digging into the system. I'll keep you posted.