HVAC Questions
 

I got my new heater/AC controls because one of the levers on mine was broken. I started labeling everything and unhooking the cables, wiring, and vacuum lines and realized something odd. The cable that goes behind the glove box had a really sharp bend in it that wouldn't let the cable move freely. This (coincidentally) was the same cable the broken lever was connected to. So it would seem at some point someone either crossed up the cables or installed a cable much too short to function properly. I know thats not the question but it lead me to start looking at the rest of the setup to make sure it looked correct.

Then I realized after hooking everything back up and checking it out that the vacuum setup seemed odd. So here are the questions:

The top lever on the front of the AC/heater controls from left to right says

INSIDE - AIR - OUTSIDE - DEFROST

#1 When the top lever is all the way to the left (on the "INSIDE" mark) the vent on the passenger side opens. Shouldn't the vent open when the top lever is on "OUTSIDE" and not "INSIDE"?

#2 The vacuum switch on top of the heater/AC control only has (2) lines coming off of it on ports #2 and #3. Port #1 is blocked off. Is that correct?

#3 With the top lever all the way to the left I can hear a faint sound of a vacuum leak coming from that switch. It doesn't seem to affect anything and I can only hear when I am under the dash. Is that normal?

Thanks for any help or advice you can give.

Jimmie

Re: HVAC Questions
 

http://67-72chevytrucks.com/vboard/s...d.php?t=689992

Check out this thread.

Re: HVAC Questions
 

The kick panel is open to let the air in the cab keep circulating to cool off the cab quicker.
The outside flapper is closed when it's all the way to the left. The one under the cowl. That's the one that lets outside air into the cab.

#2 The vacuum switch on top of the heater/AC control only has (2) lines coming off of it on ports #2 and #3. Port #1 is blocked off. Is that correct?

http://i1233.photobucket.com/albums/...holevacume.jpg

If you have the 3 vacuum ports then it need to look like the picture above.
No vacuum leak, if it's leaking you have a problem.:chevy:

http://i1233.photobucket.com/albums/...ecs/Vacuum.jpg

Re: HVAC Questions
 

Okay, thanks guys. That helps a lot. Does anyone have a part number or know where I can pick up a vacuum switch without having to buy the whole control assembly?