A/C vacuum line routeing?

[nawlins-tim]

After a semi-recent motor swap on my 1980 Elky I seem to have those 2 ,thin ,lines for the opperation of the a/c and heat leftover. Now, after doing a search on this site I found out that one worked the hot water valve and the other to a vacuum source. MY QUESTION IS WHICH LINE GOES TO WHAT? (PURPLE LINE AND GREY LINE).AND WHAT IS THAT VACUUM BULB FOR . ALL HELP APPRECIATED.
I also heard that I could cap off the heater valve one. Is this true? My heater core is leaking at the inlets. This whole thing started after I got everything cleaned up and working .With a A/C new compressor and hoses,and all the necessary brackets. Then when I turn the A/C on , especially at idle, the motor will kill if I let it. So I figured that since I barely have any vacuum to start with, with the a/c operating the vent doors it just sucks the last bit of vacuum from my motor. and I probably have the lines going to the wrong sources. I guess I could try and block off one line and have one going to a good vacuum source. Then switch. But what about the vacuum bulb? I don't know .......any ideas???

 

[O. D. Showtime]

Here's a pic of my son's 81 Malibu before we swapped in the new motor...you can see in the upper left corner of the pic...the purple line to the vacuum ball and the gray one to the heater valve. you can also see the black line from the ball which I believe runs to a T fitting in the manifold.

I can't recall what it's called but seems to me there was a solenoid that kicked up the idle when the AC was on you can see it here just above the PCV hose at the front of the throttle linkeage....it fastens to the side of the carb.

 

[carmangary]

On mine a tan one goes to the heater valve. A black one goes from that black ball resevoir to the manifold. So, in your case, just hook the one to the heater valve that does NOT come from that black ball on the fender.