Eddie 70

I have known that this was wrong for a while now, I just haven`t done anything about it. The problem is, no matter where I place the dial on the console I only get air flow from the defroster and floor vents. Anyone have any ideas why this is happening. What can I check to correct this situation?
The car doesn`t have a/c so that part is out. The vacuum lines are connected to the dial. I didn`t chase them after that.

Thanks for any help you can give.

Alwyn678

Have you checked out the ductwork under the dash....How about the dial is it functioning correctly and fully engaging....Sounds like you may have to pull the passenger side dash out and check it out

thejaf

Sounds like you need to spend some time behind the dash :cry

There are several vacuum actuators (sp) that control air flow direction. Could be something as simple and stupid as a retaining clip fell out and the actuator arm doesn't make contact with the door, although more than likely it's the actuator itself. Could also be your switch.

I've never done this, but seems to me you could try and troubleshoot by removing the vacuum lines 1 at a time and wiht the blower fan on high, use a hand vacuum pump with inline gauge to see:

1) if the door moves
2) does the vacuum actuator hold vacuum
3) is air getting to your vents

Now, you did makes sure that your vents are open, yes? :D

70blueshark

I had a similar problem, I could not stop the air flow that came in from the floor vents at all. It turned out to be something as simple as the gasket around the kick pannel vent door had rotted away. Unfortuantley it is a pain in the butt to get in there to work on it.
If that is your problem The Last Detail (www.tld-corvette.com) may have the gasket.

V8yunkie

I reworked all my heating system and from that experience, I would recommend to check wether there is any vacuum comming to the dial-control at all - so check that line first! Mine was disconnected. There is a small T-connector in front of the right-hand firewall which in my case was plugged and is easily overseen. Once you have got that OK, check the actuators: One of mine flaps got stuck, another one's linkage was broke. The actuators itself were all OK. You can try function by sucking air with your mouth through the hoses. Then renew all seals, repair cracks in the ducts with fibre-glass and put it back together - it is great to have a working heat system. Especially in cold ole Germany...

Good luck!

Techno

If it turns out to be the Vacuum controller in the heater control you can drill the rivet out and lap the 2 halves. Shouldn't take much. Then lightly grease and bolt it together. Prefably use vacuum grease or O-ring grease, silicon grease.
If nothing else is causing the problem check this last. It's a circular valve that when rotated aligns another port to vacuum, if it leaks then you don't get the valving.

Eddie 70

This morning while driving home I noticed that the air will not stop coming from the defrost duct no matter where the dial is. The indicator will travel up and down dial and airflow to the floor vents does change(airflow from floor vent goes away). I know the drivers side duct does not make it to the dash though. The passengers side does come to the dash but I do not know about air flow there. Obviously more troubleshooting needed.

:confused:

daily_driver

heh this is something i have to fix in the next coupla weaks..

first i have to find some @#@#!! ducts.....

then swap out the heater core....

:cry :cry