Vacuum source for heater/ac controls.
Thread Starter
Melting Slicks
Joined: Oct 2005
Posts: 2,056
Likes: 8
From: Redruth Cornwall
Vacuum source for heater/ac controls.
Whilst thinking about where to start tracing the vac leak I have on the headlights, I found a hissing noise coming from the dash area around the heater controls.
I wondered if a leak on the heating side of things would affect the lights. In all the vac trouble shooting posts I have read, none mention checking the heating system.
Where would the vac source for the heating system be?
If it makes any difference, its on a 79 L82.
I know there is a damaged line ( ie cut off ) that goes to what appears to be the water diverter valve.
I wondered if a leak on the heating side of things would affect the lights. In all the vac trouble shooting posts I have read, none mention checking the heating system.
Where would the vac source for the heating system be?
If it makes any difference, its on a 79 L82.
I know there is a damaged line ( ie cut off ) that goes to what appears to be the water diverter valve.
Race Director
Joined: Apr 1999
Posts: 11,520
Likes: 13
From: CORVETTE 77 385 C.I. TEXAS
A/C Vent Heat vacuum source is at the intake. There are typically several vac. connections at the intake source.
A/C Vent Heat vacuum source is a small black plastic tube that goes in below the hood alarm switch, pass. side of dist. into wiper valley.
If the vac. switch has a leak, the plastic rivet is usually not holding the 2 main switch parts together well. Besides replacing, it is also possible to tighten this &/or lube w/ a thin layer of white lithium grease to fix.
Block or fix cut off heater valve tube.
A/C Vent Heat vacuum source is a small black plastic tube that goes in below the hood alarm switch, pass. side of dist. into wiper valley.
If the vac. switch has a leak, the plastic rivet is usually not holding the 2 main switch parts together well. Besides replacing, it is also possible to tighten this &/or lube w/ a thin layer of white lithium grease to fix.
Block or fix cut off heater valve tube.
Le Mans Master
Joined: Mar 2001
Posts: 6,640
Likes: 287
From: Ann Arbor Michigan
Our friends at Wilcox have an excellent vacuum routing guide.
Gary
http://willcoxcorvette.com/instructi...ted_080509.pdf
Gary
http://willcoxcorvette.com/instructi...ted_080509.pdf
Thread Starter
Melting Slicks
Joined: Oct 2005
Posts: 2,056
Likes: 8
From: Redruth Cornwall
Our friends at Wilcox have an excellent vacuum routing guide.
Gary
http://willcoxcorvette.com/instructi...ted_080509.pdf
Gary
http://willcoxcorvette.com/instructi...ted_080509.pdf
Just searched my PC and found another willcox pdf showing the routing but not exactly where it connects to the source. Will have to double check mine tomorrow.
Last edited by jotto; Feb 21, 2010 at 03:18 PM.
Race Director
Joined: Apr 1999
Posts: 11,520
Likes: 13
From: CORVETTE 77 385 C.I. TEXAS
Safety Car
Joined: Oct 2006
Posts: 3,993
Likes: 9
From: Gig Harbor WA
I have a similar problem, as my headlights come up then go down at engine startup, otherwise work normally.
The diagrams dont show WHERE the heater vacuum T's off the system. I removed mine with the Vintage Air, but dont recall where the heater system source vacuum came from (I know its from intake, but where does it branch off the main system??)
Rob
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Thread Starter
Melting Slicks
Joined: Oct 2005
Posts: 2,056
Likes: 8
From: Redruth Cornwall
Thread Starter
Melting Slicks
Joined: Oct 2005
Posts: 2,056
Likes: 8
From: Redruth Cornwall
I should probably start a new thread for this question but....
Im probably going to remove the air con from my car for 2 reasons.
1, Compressor is seized and so it isnt working
2, Here in the UK, Air con isnt a big issue! lol.
Also, the only time I use the blower is to demist the screen.
So, as Im not sure what components are actually installed and working in my system, is it possible to have it simply set to only blow from the dash vents? ie, if other parts/valves are missing under the dash, can I just hook it up for just that?
I guess I need to have a look to see exactly what is in place and what is missing.
Im probably going to remove the air con from my car for 2 reasons.
1, Compressor is seized and so it isnt working
2, Here in the UK, Air con isnt a big issue! lol.
Also, the only time I use the blower is to demist the screen.
So, as Im not sure what components are actually installed and working in my system, is it possible to have it simply set to only blow from the dash vents? ie, if other parts/valves are missing under the dash, can I just hook it up for just that?
I guess I need to have a look to see exactly what is in place and what is missing.
Race Director
Joined: Apr 1999
Posts: 11,520
Likes: 13
From: CORVETTE 77 385 C.I. TEXAS
I have a similar problem, as my headlights come up then go down at engine startup, otherwise work normally.
The diagrams dont show WHERE the heater vacuum T's off the system. I removed mine with the Vintage Air, but dont recall where the heater system source vacuum came from (I know its from intake, but where does it branch off the main system??)
Rob
