Can someone show me a picture of where this line goes? I have 2002 3.0 . I need a pic of exactly where it goes. Don't try to explain cuz I won't understand. Thanks my ac don't work after head gasket job so I assume its this line.

 

That's the MAX AC vacuum hose for the heater by-pass valve

Follow the 2 heater hoses from firewall they run to the by-pass valve(if its still there), you will see a vacuum port on that valve

Looks like this: https://am-ebay-images-items.s3.amaz...1404040565.jpg

2 hoses in and 2 hose out

These are made of plastic so would often crack and leak, so people would just use 2 metal couplers to connect the 2 hoses together, delete the valve

This valve was ONLY used in MAX AC setting to cut off hot coolant flow thru the heater core in the cab for "maximum cooling" in the cab, nothing to do with temp control, its an on/off valve
That vacuum hose only has vacuum in MAX AC, so never a "vacuum leak" even in MAX AC

 

after plugging that hose in my ac still doesnt work

 

Does the fan blow air?
Can you see the AC clutch spin? That's gotta have a fuse.
A leak will drop pressure and a safety switch will stop the system.

 

Grey line has nothing to do with AC working or not working, it just shuts of heater hoses