My A/C is defaulting to the top vents. Pulled out the Vac selector and the the vac hose plug was pulled off. I put it back on and still the same problem. I’m not hearing any hiss. If this plug was off wouldn’t I hear a hiss? My car is an 83 with a 350 in it.

Thanks for the help

Jim

 

You might not hear a leak, check the hard line under the hood to make sure it is hooked up. If it is you may need to pull the unit back out and start the engine to see if the line has vacume. If it doesnt you will have to find the break.

 

Is there a way to determine which is the main feed? Looks like the hoses are color coded.

Jim

 

I do not remember the color of the main, I just know it when I see it. Oh that must sound bad. The other way would be to hook a vacume pump to the main line under the hood. If it holds pressure its fine. That one is easy to find. It is a hard line hooked into a vacume (Ball) on the right (passenger) side of the engine, with another hard vacume line leading to the engine intake.

 

Here is a shot of it. Maybe it will help.

Thanks for the help I'll start looking for that hose.

Jim

 

http://www.wegottafindearth.com/rpf/accolors.jpg

I found this image. Looks like the violet one is the feed line.

Jim

 

Yes that violet line is the main feed. If you have a vacume pump you can unplug the violet from the controler and insert the vavume pump, about 10lbs merc. If it holds the controler more than likley is okay. Then you will want to check the main from under the hood.