All I need to know if were the hardline that controls the vent selector is located. I finally got the ac working and everything but it only blows from the defrost area.

Someone told me the line was connected down at the vacuum canister near the drivers side headlight...well I checked that and there is no longer a line hooked to it. And my HVAC cannister is gone. I found two hardlines near the MAP sensor and neither of those lines did anything...is that one of the selector lines or is there a hardline somewhere else?

 

On my 82, there is a manifold vacuum source that leads to the big firewall mounted resevior. From there, it leads to the HVAC selector switch.

I'm sure I have my old resevior sitting in my room somewhere and I could probably part with it if push comes to shove, so to speak.

 

They go thru a grommet in the firewall, right?

If so, those are the lines for the heater controls, feed em vacuum and see if it works then

EDIT: If the reservor isn't hooked up, the controls will still work unless you are under a low vacuum situation (like heavy loading, WOT, etc...)

 

Which reservoir? The round one under the drivers headlight area?

I fed both of those hardlines vacuum and neither did anything. I didn't follow the line to see where it went because it is incased with wire loom. I will have to check it out tomorrow.

Is this line usually on the passenger side or the drivers side?

Note...if anyone was following my other post my gauge/line was messed up and thats why it wasn't feeding any r134a into the system. Put a regular old line with no gauge on and it went right in.

 

Ok...only place that I know of that has a grommet going through the firewall was were the cruise control stuff went through. Which was near the steering column. I may just have to tear into it tomorrow and actually find the selector switch and maybe run a rubber line all the way from that to my carb vac lines....

ahhh fun stuff.

 

The grommeted hole for the HVAC selector is more or less in the center of the firewall, behind a cylinder head roughly.



That's my HVAC resevior.

 

Look below the heater hose connections; you'll see a whole harness coming through there, totally separate from the engine or body or ECM harnesses; that's the HVAC one. It's separate because it's installed on the production line as part of the HVAC system option chosen, that's independent of everything else.

The ball, or the other style like in Stekman's pic, is a vacuum accumulator, with a check valve. It should have one connection that receives vacuum from the manifold; it stores it, and doesn't allow air to go the opposite way, so when you floor the throttle, there's still some vacuum to hold the little doors where they belong. Then one of those lines in that harness (if there are 2 on your car, some have only this one and not the other) p[lugs into the other port on that, and takes this "buffered" vacuum to the vacuum switch that's part of the control panel, and the switch sends it to whichever of the various little diaphragms are selected to make the air come out where you want it. The other of the 2 lines in the harness carries vacuum out to the heater control valve (not all cars have this, ones that don't, also won't have this second line) when the temp lever is in a position that calls for heat.

You need a vacuum reservoir; either the one like in the pic that was used on these early carb cars, or the ball style one that was used on ALOT of cars from the 70s on up. Otherwise you'll have the problem where everytime you give the car the gas pedal, the little doors and the HCV change their position.

The system is really simple; supply, buffer, switch, vacuum motors. The "supply" can be any port that supplies full manifold vacuum; usually on a carbed car, they used the fitting on top if the intake between the carb and the dist.

 

Ok I have the reservoir near the headlight. I will look for the correct vacuum line today once I find it I will run it to the reservoir.

 

Awesome. The ac works great now. Nice and cold and through the vents. I didn't have enough vacuum line to run it to the vacuum reservoir so I didn't. I just took a drive and even under WOT its blowing through the vents. So I guess I'll leave it as-is unless it starts acting up.