Need help!
Thread Starter
Burning Brakes
Joined: Oct 2009
Posts: 773
Likes: 2
From: Minneapolis MN
Need help!
This is my first time posting as I am new member.I am a technician by trade & hope someone has any advice before I tear apart my dash.The setting for controlling air from defrost to vent to floor is not working properly.No matter what setting I put on being vent or floor only,only get air out of defrost & floor.I replaced HVAC unit(buttons) thinking this would fix problem & because a bulb was burnt out in HVAC unit,but it did not fix.I hear no vacuum leaks underdash or behind radio.I'm assuming programmer is bad,but hope someone here had a similiar problem.by the way my vehicle is a 1994 corvette coupe with electronic air.HELP!
Race Director
Joined: Sep 2003
Posts: 16,834
Likes: 337
From: Database Error Indiana
Look under the hood for a vacuum check valve. May be under the passenger side fuel rail cover. These are known to break and screw up the operation of the vac door under the dash.
Safety Car
Joined: Jun 2006
Posts: 3,629
Likes: 28
From: FL
Remove the right side fuel rail cover by lifting straight up, the nipples break off the three port check valve shown below (black & white plastic piece).
Available from nearly any parts store, local dealer or forum vendors GM Parts Direct, GM Parts House etc. GM Part Number
15733271, less than $10 even from a dealer
