1973 ventilation and air con issues
01-13-2017, 07:13 PM
#41
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Just out of interest, someone on eBay has a control unit for sale that seems to have the same controls as mine on both sides:
http://www.ebay.com/itm/1968-1976-Co...25.m3641.l6368
Please note that I'm not suggesting the seller is an expert in dating Corvette parts, but his ad does suggest some years were set up the same as mine currently is. Maybe 1975 on as F4Gary states?
Regards
John
http://www.ebay.com/itm/1968-1976-Co...25.m3641.l6368
Please note that I'm not suggesting the seller is an expert in dating Corvette parts, but his ad does suggest some years were set up the same as mine currently is. Maybe 1975 on as F4Gary states?
Regards
John
01-13-2017, 09:24 PM
#42
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I've been battling this sort of the thing also. Just started another thread this morning. My 73 has the vacuum switch on top of the interior side of heater a/c housing that that controls vacuum to the water valve. Someone at sometime replaced, added or what ever one on my car. I've searched every page of the AIM and those parts (water control valve or vacuum switch) are not included. According to the 1973 Chevrolet service manual page 1A-85 " The water valve is used on Chevelle 116" W.B. station Wagon and Monte Carlo models only. I'll install a shutoff valve to keep the hot water from circulating through heater core during the warm season. Been this way with almost everything on this challenge. You guys that have cars that haven't been hacked on, congratulations.
01-13-2017, 09:50 PM
#43
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Well, his response was:
"I can't remember exactly what year it came out of but it will work from 68-76...thanks Zore"
So that doesn't really help.
"I can't remember exactly what year it came out of but it will work from 68-76...thanks Zore"
So that doesn't really help.
01-14-2017, 01:07 PM
#44
Instructor
I have a 1973 Corvette and am having trouble with the vacuum ventilation system. The attached photo shows the control unit with the car. You will see on the left a large 6 outlet vacuum switch and on the right a smaller 3 outlet vacuum switch. The 73 AIM only shows the larger left hand switch and no right hand switch. Different model year diagrams show s a similar right hand 3 outlet switch but this is paired with another small 3 outlet switch on the left side. I can’t find any diagrams that shows both 6 outlet and a 3 outlet switches. The problem I am having is that when the left hand control wheel is moved to “HTR” or the right hand control wheel is moved off “C”, I lose all vacuum. Can anyone help.
I've tried to attach the photo but if it doesn't work, I hope the words explain it.
John
I've tried to attach the photo but if it doesn't work, I hope the words explain it.
John
Temperature Control
This control operates the temperature door through use of a bowden cable. In "COLD" no airflow is allowed through the heater core. In "HOT" all air flows through the heater core. This control also operates an override vacuum switch which closes the water shut off valve when placed in the maximum cold position and will put the system into outiside air whenever heat is called for, regardless of the position of the selector control.
01-14-2017, 02:02 PM
#45
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I was reading through my 69 Service manual and found something that might explain those vacuum hoses:
Temperature Control
This control operates the temperature door through use of a bowden cable. In "COLD" no airflow is allowed through the heater core. In "HOT" all air flows through the heater core. This control also operates an override vacuum switch which closes the water shut off valve when placed in the maximum cold position and will put the system into outiside air whenever heat is called for, regardless of the position of the selector control.
Temperature Control
This control operates the temperature door through use of a bowden cable. In "COLD" no airflow is allowed through the heater core. In "HOT" all air flows through the heater core. This control also operates an override vacuum switch which closes the water shut off valve when placed in the maximum cold position and will put the system into outiside air whenever heat is called for, regardless of the position of the selector control.
01-14-2017, 02:14 PM
#46
Instructor