black one goes to your manifold, on ed its a plastic tee on the back of the manifold along with the hose that comes off your booster... Green hooks to your heater tap... Down Under the back of the manifold...

On my ed falcon, its was caused by the change over flap above the hand brake. The arm on the door on the inside of the duct had snapped off... So when the vacuum solenoid pulled on it didn't actually pull on the door...

Cheers,
Tim

Thanks Evan.
Yes, it plugged into a rubber boot thing. Was in a mongrel of a spot to see. Now car idles smoother too, so must have been sucking in a bit air.
Cheers,
Ken.

You were spot on Tim. Thanks. I had replaced water bottle a couple of months ago, and must have bumped it then.