Togo

I have an AC problem, i can run the AC, it blows real cold, only thing is, is that it only blows bi-level, and it only brings in fresh air. (never had the dash apart, YET! and i did replace the blower motor, but thats it....honest!) could this be a vacuum switch? think i gotta take the dash apart cuz there's a door stuck???? if anyone has had this problem, let me know, as i am going to have the heater core replaced in a couple of months, so if its under the dash, they will fix it then. if its as simple as the vacuum switch, then how do i change that????
thanks in advance for all your help, this forum kicks some serious TAIL! glad i found all you guys (and girls if there are any of you out there!)

R Cook 92

Yes the heater core will, have to be accessed from under the dash( 99% sure, thats the way my 92 is...)(I'm assuming you've got an 85.) I'd definately have them do it if they are deep in the dash at your A/C programmer, or any of the vaccum lines...

Does nothing blow when you press the other A/C settings? and it is blowing cold outside air in Arizona???? The bi-level setting should only be able to cool the car to the temp outside...you might have a problem with your A/C head unit...

Let us konw.
Randy
92 auto coupe.

Togo

thanks for the info randy....as a matter of fact, it blows very cold air...cold enough to cool off the entire car with the top on and windows up. and it blows "bi-level" on all 3 A/C settings.....norm, max, and bi-level. and no cool air is escaping to try to cool down sunny AZ! let me know if there is anything else to check!
thanks

89 Bob L

There is a possibility it could be a vacum line, the programmer or a bad connection with the climate control module.

As with the engine, you can troubleshoot by pulling codes. Anyone out there have the setps to pull the codes for an 85?

Corvette ED

It sound like a vacum problem. I think there is a small vacum valve on the intake that goes bad and this could be the problem, or the door is not changing to let the air come out of the vents.

NHVett

Had the same problem w/my 85 when I got it. Turned out to be a cracked vacuum line. The hard plastic vacuum HVAC line runs from the rear of the plenum down into a large wire harness at the base of the distrubutor over the bell housing and down below the heater where it goes through the firewall to the vacuum distribution block for the heater/ac. I just ran a new rubber vacuum hose from a tee at the plenum rear vacuum connection, around and down to where the old line runs through the firewall and tapped in. See if you can locate the original thin black plastic vacuum line below the heater and remove the rubber elbow you will see, with the engine running, you will have vacuum if the line is not broken or cracked.