Vent Always On and Blowing Hot Air!?! - Team Camaro Tech
Heating & Cooling Heating, cooling and air conditioning

Reply
 
LinkBack Thread Tools Display Modes
post #1 of 34 (permalink) Old Jun 30th, 11, 11:04 AM Thread Starter
Senior Tech
 
Join Date: Mar 2011
Location: Greenville, SC
Posts: 120
Vent Always On and Blowing Hot Air!?!

My 68' Camaro has factory air and pretty much everything appears to be working as it should. The one exception being that the air vent is always on and the air coming out of it is HOT, like heater or hot engine bay hot!

You don't notice the air or how hot it is until the car is very warm and you feel like you are sitting in an oven!

With all three HVAC sliders all the way to the left and the fan selector all the way up (off) there is no air coming out of the vents AT A STOP. As soon as you start driving hot air starts coming out of the vents!

This is preventing me from enjoying the car so I could really use your guys help.

Where do I look first?
Formula51 is offline  
Sponsored Links
Advertisement
 
post #2 of 34 (permalink) Old Jun 30th, 11, 07:03 PM
Super Moderator
Bess-68's rule
 
Everett#2390's Avatar
 
Join Date: Sep 2000
Location: Va Beach VA
Posts: 32,159
Garage
Re: Vent Always On and Blowing Hot Air!?!

In the cowl area, I believe, there is a vacuum actuator to let in outside air.
This actuator is normal open by design. With TEMP in the OFF position, vacuum is applied to close the actuator.

Vacuum source comes from the intake through the firewall to a plug connecting to the vacuum switch on the TEMP control. Then vacuum is routed over to the actuator to close it. Could be a cracked/broken hose or vacuum switch, the plug fell off, TEMP cable misadjusted, actuator diaphram broken. Very common for neoprene hoses to dry rot and/or split at tees and connectors - vacuum leak. A hand vacuum pump comes in very handy for these type of problems. Hose routing is behind glovebox and above heater, of course.

Give a man a rescued dog for the health of both their souls. May 2017 ROTM Winner - Thank you!
'
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
CUBS - 2016 World Series Champions - Thank you, Joe Madden enjoy your next chapter.
Everett#2390 is offline  
post #3 of 34 (permalink) Old Jun 30th, 11, 09:41 PM
Senior Tech
Steps
 
Join Date: Dec 2005
Location: New Zealand
Posts: 13,321
Re: Vent Always On and Blowing Hot Air!?!

What everett says above
OR
When the heater was assembled, the 2 flaps where put in in the wrong order....very easy done...I have done that a couple times over the decades.

My Spelling is not incorrect...it is creative

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Steptoe is offline  
 
post #4 of 34 (permalink) Old Jul 1st, 11, 06:29 AM
Retired
Jim
 
click's Avatar
 
Join Date: Jun 2001
Location: Central Minnesota
Posts: 15,998
Re: Vent Always On and Blowing Hot Air!?!

Here is my cowl a/c dampner... fyi

Click image for larger version

Name:	CowlA-CDamper.JPG
Views:	319
Size:	121.3 KB
ID:	23202

Click..is Jim..former owner of a 69RS-LM1 350/255 - 700r
"There will come a time when you believe everything is finished,
That will be the beginning." Louis L'Amour
click is offline  
post #5 of 34 (permalink) Old Jul 7th, 11, 07:27 AM Thread Starter
Senior Tech
 
Join Date: Mar 2011
Location: Greenville, SC
Posts: 120
Re: Vent Always On and Blowing Hot Air!?!

I have the cowl AC dampner mentioned above and the vacuum line is attached. I checked all the vacuum lines I could find and they were all good.

I could not find a vacuum switch, but I think you guys are on to something with the cable being misadjusted. When I got the car it had a piece of paper folded up and stuck in the top HVAC slot. This paper is necessary to keep the slide lever in the "OFF" position. Without the paper, the slide lever is very easy to move compared to the other two and will slide over into the AC position and the AC would run all the time.

Perhaps the lever is not actually reaching the "OFF" position, but is only going into the "VENT" position. How would I go about adjusting this lever? Do I need to take the dash apart or can I get to it from underneath? Thanks.
Formula51 is offline  
post #6 of 34 (permalink) Old Jul 7th, 11, 09:21 AM
Super Moderator
Bess-68's rule
 
Everett#2390's Avatar
 
Join Date: Sep 2000
Location: Va Beach VA
Posts: 32,159
Garage
Re: Vent Always On and Blowing Hot Air!?!

Vacuum switch is attached to the heater control, top lever, left hand side and can be accessed from the dash underneath - might need a third joint in the arm/hand.

The far end of the cable is adjustable in the clamp. You might have to remove the glovebox, very easy, and work from the dangling door opening. Loosen the clamp, 1/4 inch socket, and slide the cable casing towards the heater control, tighten clamp. Might need to wrap casing with electrical tape for a better clamp grip. Reinstall glovebox only after road testing.

Beg/borrow/steal/cumshaw a hand vacuum pump and attach to outgoing vacuum line and test actuator and road test.

Give a man a rescued dog for the health of both their souls. May 2017 ROTM Winner - Thank you!
'
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
CUBS - 2016 World Series Champions - Thank you, Joe Madden enjoy your next chapter.
Everett#2390 is offline  
post #7 of 34 (permalink) Old Sep 13th, 11, 04:05 PM Thread Starter
Senior Tech
 
Join Date: Mar 2011
Location: Greenville, SC
Posts: 120
Re: Vent Always On and Blowing Hot Air!?!

Update. Finally got to pulling out the old CD player (in the glovebox) and found the cable you guys are talking about.

When I move the top lever or should I say let it flop around, it does not move the cable one bit. It appears it is disconnected/broken at the HVAC control unit itself. Does this diagnosis sound correct? If I move the middle HVAC lever, I can see it move the other cable and a nearby black metal lever on top the heater box.

The black metal lever moved by the middle HVAC lever is circled in red in the attachment. The other cable in the picture is the one that does not move.


Looks like the next thing to do is to pull the center of the dash off and slide it out and take a look. Any tips on how to do that? It looks like there are two screws on the bottom corners and thats it....maybe some clips....? I just don't want to break anything.

Thanks,
Eddie

Last edited by Formula51; Feb 3rd, 12 at 12:09 PM.
Formula51 is offline  
post #8 of 34 (permalink) Old Sep 13th, 11, 04:19 PM
Super Moderator
Bess-68's rule
 
Everett#2390's Avatar
 
Join Date: Sep 2000
Location: Va Beach VA
Posts: 32,159
Garage
Re: Vent Always On and Blowing Hot Air!?!

The cable at the rear does not move, correct?
Loosen the clamp screw and move the whole cable assembly just to see if the cable is broke or the door it controls is stuck.

Yes, remove the center plate be removing the lower screws and the ashtray bracket, then lift up to unhook the panel from the clip.
Careful, the top clip is plastic and brittle.
Once the panel is off, you will see the screws on either to loosen to remove the HVAC control head.

Give a man a rescued dog for the health of both their souls. May 2017 ROTM Winner - Thank you!
'
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
CUBS - 2016 World Series Champions - Thank you, Joe Madden enjoy your next chapter.
Everett#2390 is offline  
post #9 of 34 (permalink) Old Sep 13th, 11, 11:26 PM
Senior Tech
Steps
 
Join Date: Dec 2005
Location: New Zealand
Posts: 13,321
Re: Vent Always On and Blowing Hot Air!?!

Check that the flaps where not put in in the wrong order as my post above...gives the same symtoms....been there done that, and sad to say several times over the yrs lol

My Spelling is not incorrect...it is creative

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Steptoe is offline  
post #10 of 34 (permalink) Old Sep 14th, 11, 05:53 AM Thread Starter
Senior Tech
 
Join Date: Mar 2011
Location: Greenville, SC
Posts: 120
Re: Vent Always On and Blowing Hot Air!?!

I don't understand how to "check" if the flaps were put in wrong? Does my picture describing which flap works (or doesnt work) with each lever explain it?
Formula51 is offline  
post #11 of 34 (permalink) Old Sep 14th, 11, 01:43 PM
Senior Tech
Steps
 
Join Date: Dec 2005
Location: New Zealand
Posts: 13,321
Re: Vent Always On and Blowing Hot Air!?!

can you manually move the flaps and everything works fine?
If the flaps are installed in the wrong order then they hook up on each other and dont open and close the different parts of the heater box and u get hot air instead of cold or visa versa and stuff.

My Spelling is not incorrect...it is creative

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Steptoe is offline  
post #12 of 34 (permalink) Old Sep 15th, 11, 06:09 PM Thread Starter
Senior Tech
 
Join Date: Mar 2011
Location: Greenville, SC
Posts: 120
Re: Vent Always On and Blowing Hot Air!?!

Progress.....kind of.

I took the bracket screw loose at the flapper door and moved the cable by hand and it opened and closed the door. There did not appear to be any obstruction or binding. Check.

Took the center dash apart and what fun that was. The tuner knob for the radio had a washer and capture nut (like what you hold a fender emblem on with) pushed on the shaft to hold the radio bezel in place. When I finally got it off, the radio just fell into the dash. Uh oh, new problem.

The power knob closest to drivers side had the proper threaded outer shaft with a 5/8" nut. I assume the passenger side should have the same thing and I can see the threaded outer shaft down in the radio! What fun. Are those two nuts (around the knob shafts) and tightened up against the radio bezel the only thing that hold the radio in place? It seams like it would bounce around with just those, is there another bracket or something I am missing? It appears the radio was just leaning against the ash tray housing and someone had added some black tape to keep it from bouncing around too much. Don't you just love other people's messes! I might have to start a new topic for this one.

On to the HVAC lever. It appears all the cables are connected. It also appears a stud/rivet/spot weld not sure what you call it has broken lose on that top lever and that is what is allowing it to flop around. See the two red holes in the pic below:




If I line up the holes and stick something through them, the lever still works and appears to get firmer. I did not hook up the flapper door cable bracket to test yet. Does this sound like the problem? If so, any suggestions on what to use to fix it? Maybe I can get a screw to tap into those two pieces....it looks like it would be a real pain to get the HVAC unit out of the dash. Do you have to take it out from the bottom? I can't see how it comes out of the dash since the tabs on the side are behind the main metal part of the dash....

Next thing. From what I can see, all of the electrical connections look hooked up and everything worked (except the vent flapper door) since I have been driving the car. HOWEVER, I found a three spade connection with a black and green wire running to it just haning out up by the HVAC unit:



Any idea what that connection goes to?

Man oh man, it's never simple!

A sincere thanks for all of the help guys.
Formula51 is offline  
post #13 of 34 (permalink) Old Sep 15th, 11, 06:36 PM
Super Moderator
Bess-68's rule
 
Everett#2390's Avatar
 
Join Date: Sep 2000
Location: Va Beach VA
Posts: 32,159
Garage
Re: Vent Always On and Blowing Hot Air!?!

Good work! Why not a 6-32 screw and a locknut on the other side?
You would need to put in a bronze bushing to prevent the pot metal lever from wearing out over time.
Yes, hook up the cable to see/feel the firmness.

Connector could be for the vent not working?

Give a man a rescued dog for the health of both their souls. May 2017 ROTM Winner - Thank you!
'
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
CUBS - 2016 World Series Champions - Thank you, Joe Madden enjoy your next chapter.
Everett#2390 is offline  
post #14 of 34 (permalink) Old Sep 15th, 11, 07:49 PM
Senior Tech
 
Join Date: Jan 2001
Location: Garden Ridge Tx. USA
Posts: 1,927
Re: Vent Always On and Blowing Hot Air!?!

"It also appears a stud/rivet/spot weld not sure what you call it has broken lose on that top lever and that is what is allowing it to flop around."
It looks like the lever is broken in half (Very common) and someone tried to patch it back together, replacements are available in repops. The electrical connector looks like the factory plug for the radio.

Ron
The
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

An exercise in interchangeability on a Well optioned 67 SS 350 vert.
Geezer is offline  
post #15 of 34 (permalink) Old Sep 15th, 11, 09:03 PM
Super Moderator
Bess-68's rule
 
Everett#2390's Avatar
 
Join Date: Sep 2000
Location: Va Beach VA
Posts: 32,159
Garage
Re: Vent Always On and Blowing Hot Air!?!

For OE radio, there should be a strap at the rear pass side corner for support from the brace above radio.

Give a man a rescued dog for the health of both their souls. May 2017 ROTM Winner - Thank you!
'
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
CUBS - 2016 World Series Champions - Thank you, Joe Madden enjoy your next chapter.
Everett#2390 is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Team Camaro Tech forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address.
NOTE we receive a lot of registrations with bad email addresses. IF you do not receive your confirmation email you will not be able to post. contact support and we will try and help.
Be sure you enter a valid email address and check your spam folder as well.



Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome