68 Non-AC Heater Controls
Thread Starter
Burning Brakes
Joined: Oct 2000
Posts: 779
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From: Minneapolis MN
68 Non-AC Heater Controls
As long as I'm replacing the wrong-year shifter console on my 68, I figured I'd sort out the heater controls.
My left heater control wheel has never wanted to go up toward Off because of the cable being broken due to the flapper being stuck - no big deal I'll figure that out.
However I can NOT figure out what purpose the vacuum control valves serve. I don't see ANY heater or air-flow related vacuum solenoids in my car. Everything is cable-actuated.
What do the vacuum valves do in a 68 non-AC?
My left heater control wheel has never wanted to go up toward Off because of the cable being broken due to the flapper being stuck - no big deal I'll figure that out.
However I can NOT figure out what purpose the vacuum control valves serve. I don't see ANY heater or air-flow related vacuum solenoids in my car. Everything is cable-actuated.
What do the vacuum valves do in a 68 non-AC?
Le Mans Master
Joined: Jun 2005
Posts: 5,447
Likes: 3
From: Syracuse NY
Nothing, I'd guess that the wrong year shifter plate included the heater controls that you have.
Starting in '69 and possibly for the rest of the C3 series( I'm not sure ) the heater/defroster controls used vacuum as well as cables. There was an actuator located on top of the heater housing that the '68 doesn't have.
I might have a '68 heater control if you'd like the correct parts. You can buy the controls repo'd as well. Check with Willcox.
I just wanted to add that the settings are different on the '68.
Check these links to see the differences.
Here's the '68
http://www.ecklers.com/corvette-heat...anel-1968.html
and the '69
http://www.ecklers.com/corvette-heat...anel-1969-1971
Starting in '69 and possibly for the rest of the C3 series( I'm not sure ) the heater/defroster controls used vacuum as well as cables. There was an actuator located on top of the heater housing that the '68 doesn't have.
I might have a '68 heater control if you'd like the correct parts. You can buy the controls repo'd as well. Check with Willcox.
I just wanted to add that the settings are different on the '68.
Check these links to see the differences.
Here's the '68
http://www.ecklers.com/corvette-heat...anel-1968.html
and the '69
http://www.ecklers.com/corvette-heat...anel-1969-1971
Last edited by DZRick; Feb 28, 2011 at 04:32 AM.
Team Owner
Joined: Jan 2006
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From: Crossville TN
You have a vacuum distribution manifold on the left side of the heater control head. It 'sends' vacuum to the damper door servos so that appropriate ducting is selected when the left (function selector) wheel is moved. That is how heater or vent air is directed to the "heat" and/or "de-fog" outlets.
That vacuum distribution valve eliminates the need for additional solenoid valves.
That vacuum distribution valve eliminates the need for additional solenoid valves.
Last edited by 7T1vette; Feb 28, 2011 at 09:58 AM.
Thread Starter
Burning Brakes
Joined: Oct 2000
Posts: 779
Likes: 1
From: Minneapolis MN
I guess that would explain my confusion then.
I just double-checked and it definitely has the 1968 heater control markings but has the 2 vacuum manifolds with hoses that from what I can tell are hooked up but lead to nowhere.
The guy who did the restoration work on my 68 was a moron.
I just double-checked and it definitely has the 1968 heater control markings but has the 2 vacuum manifolds with hoses that from what I can tell are hooked up but lead to nowhere.
The guy who did the restoration work on my 68 was a moron.
Thread Starter
Burning Brakes
Joined: Oct 2000
Posts: 779
Likes: 1
From: Minneapolis MN
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Le Mans Master
Joined: Jun 2005
Posts: 5,447
Likes: 3
From: Syracuse NY
I apologize if I gave incorrect info but I don't remember any vacuum involved on either of my non-air '68s and I just replaced my heater controls last summer.
I'd appreciate a picture of a '68 if anyone has one.
I'd appreciate a picture of a '68 if anyone has one.
Thread Starter
Burning Brakes
Joined: Oct 2000
Posts: 779
Likes: 1
From: Minneapolis MN
DZRick I am inclined to believe you are correct. I can't find any heater/cooling/damper related actuator of any kind. If there's no actuator, what would I ever need vacuum for.
Furthermore, the mechanical cables seem to actuate all the arms and functions of the ducting that I can think of.
Is it possible that the heater controls are correct for '68, but someone attached a '69-later vacuum manifold to it thinking it was necessary?
As I said before, from my cursory inspection, the hoses connected to the manifold simply go nowhere.
Furthermore, the mechanical cables seem to actuate all the arms and functions of the ducting that I can think of.
Is it possible that the heater controls are correct for '68, but someone attached a '69-later vacuum manifold to it thinking it was necessary?
As I said before, from my cursory inspection, the hoses connected to the manifold simply go nowhere.
Le Mans Master
Joined: Jun 2005
Posts: 5,447
Likes: 3
From: Syracuse NY
DZRick I am inclined to believe you are correct. I can't find any heater/cooling/damper related actuator of any kind. If there's no actuator, what would I ever need vacuum for.
Furthermore, the mechanical cables seem to actuate all the arms and functions of the ducting that I can think of.
Is it possible that the heater controls are correct for '68, but someone attached a '69-later vacuum manifold to it thinking it was necessary?
As I said before, from my cursory inspection, the hoses connected to the manifold simply go nowhere.
Furthermore, the mechanical cables seem to actuate all the arms and functions of the ducting that I can think of.
Is it possible that the heater controls are correct for '68, but someone attached a '69-later vacuum manifold to it thinking it was necessary?
As I said before, from my cursory inspection, the hoses connected to the manifold simply go nowhere.
All the setting/lettering is on the lens, your lens might have been swapped from a '68 onto a later year heater control in your case, it's easy to swap the lens.
Le Mans Master
Joined: Jun 2005
Posts: 5,447
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From: Syracuse NY
Team Owner
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...I thought it was this way too when I did my heater core and heater control switch system on my '68 convertible a decade ago.
...thought the '68 was the only C3 to be this way?
...when I changed my old '75 coupe to an A/C DELETE car, I made sure to have a '69 & up inner heater box and controls for this very same reason.
...thought the '68 was the only C3 to be this way?
...when I changed my old '75 coupe to an A/C DELETE car, I made sure to have a '69 & up inner heater box and controls for this very same reason.
Le Mans Master
Joined: Jun 2005
Posts: 5,447
Likes: 3
From: Syracuse NY
...I thought it was this way too when I did my heater core and heater control switch system on my '68 convertible a decade ago.
...thought the '68 was the only C3 to be this way?
...when I changed my old '75 coupe to an A/C DELETE car, I made sure to have a '69 & up inner heater box and controls for this very same reason.
...thought the '68 was the only C3 to be this way?
...when I changed my old '75 coupe to an A/C DELETE car, I made sure to have a '69 & up inner heater box and controls for this very same reason.
I believe that is true, another '68 only item.
