Topic: AC Problem Cont.
in Forum: C3 Cooling and Heating Systems
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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.
Any pointers would be appreciated.
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.
Any pointers would be appreciated.
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Lifetime MemberModerator
Duncanville, TX - USA
Joined: 11/8/2003
Posts: 20214
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...
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 
(click for Texas-sized view!) NCRS
"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
Lifetime MemberModerator
Duncanville, TX - USA
Joined: 11/8/2003
Posts: 20214
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
Thanx, Robert! That first one is really nice!
The second one is from the AIM, of course...too bad it's not colored in!!
The second one is from the AIM, of course...too bad it's not colored in!!
Joel Adams
C3VR Lifetime Member #56
My Link
(click for Texas-sized view!) NCRS
"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
With the engine running and AC on pull the vacumm line off the top part of the servo closest to the gas pedal is there vacumm?
From that servo is a rod that goes toward the center of the dash if you move this arm (with the hose still off) does the air flow to the diferent spots?
in Forum: C3 Cooling and Heating Systems
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