A/C vents problem
Thread Starter
Le Mans Master
Joined: Dec 2001
Posts: 5,706
Likes: 551
From: St. Peters MO
C7 of Year Finalist (stock) 2019
2018 C7 of Year Finalist
A/C vents problem
I have a 1982 and the a/c began having a problem a few days ago.
The a/c works fine, blows very cold air but for the past few days I can't get the air to come out of the upper or side vents.
The cold air comes out of the heater vents in both normal and max settings when selected on the sliding lever. It also will blow through the defrost vent if I switch it to that posistion.
I am suspecting a diverter valve problem but am hoping it can be as simple as a loose vacuum line. If this has happened to anyone I'd sure appreciate knowing what to look for befor I start taking the console area apart.
I do have a service manual and know there are a bazillion vacuum lines back there. I also have a brand new heat a/c control assembly that I have been meaning to get around to installing and want to do that when I take the console apart as well.
Any suggestions out there?
The a/c works fine, blows very cold air but for the past few days I can't get the air to come out of the upper or side vents.
The cold air comes out of the heater vents in both normal and max settings when selected on the sliding lever. It also will blow through the defrost vent if I switch it to that posistion.
I am suspecting a diverter valve problem but am hoping it can be as simple as a loose vacuum line. If this has happened to anyone I'd sure appreciate knowing what to look for befor I start taking the console area apart.
I do have a service manual and know there are a bazillion vacuum lines back there. I also have a brand new heat a/c control assembly that I have been meaning to get around to installing and want to do that when I take the console apart as well.
Any suggestions out there?
Last edited by 2K14C7; Jun 10, 2005 at 05:27 PM.
Drifting
Joined: Oct 2004
Posts: 1,496
Likes: 1
From: Lafayette Louisiana
I believe no vacuum would only let air out of the heater vent. Since it will change to defrost I would suspect a bad selector valve or a leak in the vacuum line leaving the control valve. Sorry I don't know what the proper names of these parts are but I have worked on them before. Also check the vacuum lines that pass thru the firewall on the passenger side almost behind the dist. (3 of them together). One or more supplies vacuum to the selector.
Safety Car
Joined: Jun 2002
Posts: 4,135
Likes: 1
just go thru your vaccume system until you find the problem, do you have a vaccume diagram? its in the assembly manual. i color coded mine the same color as the tracer on the vaccume lines,and it was e/z to go thru,,,first you'll have to look at the vaccume diagram to understand what is going on when you make a selection (defrost/max air---heat ect ect) the rotary vaccume switch takes source vaccume and sends it to different accuators that you select at the console..you can unplug these accuators and apply vaccume to see if there doing what there supposed to do..then you will know by process of elimationif its a bad rotary vaccume switch,,,bad accuator..ect,,,,this system is very simple,,,you will have to take the time to look at the manual and understand how it is working,,,good luck
Drifting
Joined: Jun 2004
Posts: 1,881
Likes: 9
From: staten island ny
Have you been doing any work on the car that may have enabled you to unplug one of the vacuum hoses?
The default setting in case you lose vacuum is the heat or floorboard vent. My feeling is something became unplugged or you developed a leak very quickly somewhere else. Look at the vac line that goes into the heater core shut off valve inside the eng compartment. Mine is always getting knocked off when i fiddle with the engine.
The default setting in case you lose vacuum is the heat or floorboard vent. My feeling is something became unplugged or you developed a leak very quickly somewhere else. Look at the vac line that goes into the heater core shut off valve inside the eng compartment. Mine is always getting knocked off when i fiddle with the engine.
