I finally have vacuum coming into the interior.

So I heard a hiss inside and determined that the GREY hose was the VACUUM SUPPLY. I found the leak

The GREY and PURPLE hose are connected to a plug for something I know no name or its purpose? I know where it hooks up.

and there is about 5 hoses connected to a rotary dial, which spins when you move from Mode Selector Left and Right.

The PURPLE hose was routed from the first connector mentioned above to the rotary dial.

I thought that the rotary dial was not receiving vacuum so I jumped from the GREY vacuum source to the PURPLE and Now my vents work!!!!!

But now nothing is plugged into the first connector. What does it do??
The Hissing was coming from there at the grey hose/unknown device.

Any Clue what is going on with that device?
Is it common to go?
Is there a part???

 

Here's a pic:

https://www.thirdgen.org/forums/atta...duct010707.jpg

The info below is from my 85 Camaro shop manual:

1 input (violet) from vac source
2 recirc (orange)
3 upper mode (red)
4 lower mode (tan)
5 defrost (blue)

BTW, listing your car's year, make, model, etc. is always helpful.

JamesC

 

Thought I had included my Car
87 Iroc 5.7 w/ AC

It looks like my rotary dial is hooked up like yours.

Do you have the other piece that has a grey/purple hoses only, its about in the same spot except the other side of center. Looks like there is a hole there in your picture.


Anyone have any idea what it does??

 

On cars equipped with a diverter valve, there should be a vac hose OUT through the firewall to that diverter valve.

 

I have the same problem, but I can't find the incoming line. I have been told it's behind the distribitor. Is that true?

 

The Vacuum in and Heat diverter Out are located by the distributer. They are hard to notice if you don't know they are there.

They come out of a wire loom by the firewall, follow your passenger valve cover to the firewall. One of my hoses has about 1" that can be seen, and the other is about 3". They are hard plastic. Should be above your heater core inlets.

I am not sure if they were cut this way or if that is normal.

 

For people with the diverter valve, Is your vacuum supply from the grey or purple hose?