Vette(s): 1979 L48 Resto-Mod. ZZ383 w/ TKO-500 manual transmission. Centerforce clutch. Tail light conversion. A/C. BeCool radiator. Red exterior with custom black and white leather interior by Mid America Motorworks.
I just refurbished the AC controls...wiring harnesses...and checked my compressor. The AC system is working now...with one small problem..
When you have the AC selector in MAX or NORM...the cold air is being blown out into the footwells instead of the dash vents. If you move the selector to DEF, the system works and starts to blow the air up at the windshield.
Is there a vacuum relay somewhere that could be causing my problem? All of the vacuum diagrams and posts I have been able to find on the topic deal with the more important issue of the headlights.
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/
Am-Fm/map light National/Regional/Chapter NCRS "Top Flight"
#2-1985 Bright Red/Carmine Cp.L-98/auto
Member: NCRS, NCRS Texas, Corvette Legends of Texas
Shane, the only place I've ever seen HVAC vacuum diagrams is in the AIM(Assembly Instruction Manual)...if you do not have one of these manuals, you really need to get one. They're only about $20 from any of the Corvette parts vendors....every Corvette owner should have one.
It sounds like you have a vacuum problem, for sure. It could be one of the servos leaking, or stuck, or it might also be simply a leak in the system, or one of the vac. lines off, or in the wrong location.
Someone here posted a pic(or pics) of their car with the dash out, and all of the HVAC stuff out in the open, giving a great view of where everything is, such as the servos for the doors in the HVAC system. It was a couple of years ago, if I remember right, so it might take a little time searching for it, but I shall look and see can I find it...
____________________________________ Joel Adams C3VR Lifetime Member #56 My Link
Corvette is a registered trademark of the General Motors Corporation(GM) &
Chevrolet Motor Division. Vette Registries, LLC is responsible for all site content (except for member submitted content or where otherwise
noted) and does not claim or imply that Chevrolet or
GM is responsible for Official C3 Vette Registry content. Vette Registries, LLC is independent from GM and is not affiliated
with, sponsored or supported by GM. Copyright/trademark/sales mark
infringements are not intended, or implied and are in fact used to support
GM, Chevrolet and Corvette.
Official C3 Vette Registry content is Copyright 2001-2017, Vette Registries, LLC. Content may not be reused without written consent. All Rights Reserved. NS
Corvette (Vette) Model Years on this site: 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982