'96 Cherokee - vacuum question?

[LittleRedXJ]

Hey folks! File this under "I probably should have left well enough alone," but I have a question about my '96 4.0 Cherokee SE. I was under the driver's side of the dash trying to suss out my parking light problem. (I think I've figured that out, thanks to you all, but its late and I'm going to try to fix that later.) While I was under there, I saw a green/clear tube, vacuum I guess, hanging about where I had never seen it before. A quick glance around and I found a little black item with a spot marked in green where it looked as though this tube was supposed to be plugged in. There was also a blue tube coming off this item. I couldn't resist the urge to plug the green tube into the black item. I started her up just to make sure it was going to run correctly, and so far, so good. So, I had no problems at all before I noticed this hanging tube, including four-wheel, since I had just used it seconds before. My question is, did I do the right thing plugging that green tube in, or am I going to find out soon enough that I did something wrong? Can anyone help?

 

[heyhar]

What did you plug it in to? Did it go to the back of the HVAC? There hasn't been any vacuum related to 4WD since, I believe 1990. Possibly start the engine, remove the tube, see if there's any vac. on it. If not, cycle the HVAC through the various steps, see if any position causes vac. to appear, either at the tube or nipple where you think it goes. I'll assume the car has AC, so there's various doors that are vac. operated. Figure out what does/doesn't work before/after, and report back.