my aftermarket boost gage doesn't work

[Andrew88]

Sorry for taking so long, and thanks for your patience!! A few things...1, ok, I was wrong. At idle, it does hang around -20, so we're good there; no vacuum leak.

2, sure enough, that vacuum line traced in red DOES go into the cabin. It is spliced into a line that DOES go into the WHITE circle, NOT the blue one. (BTW, I would love to know what these circles are called so I don't have to rely on you coloring them for the sake of my own idiocy) Anyways, my previous owner was an IDIOT!

As for the yellow line, there is a white plastic tubing in there, and it also runs into the cabin, AND is also spliced into the same incorrect line (the one going into the "white circle.")

Silver Bullet, you didn't embarrass me haha. And as for the green thing on the right... Without taking anything apart, it looks like a screw with 2 nuts on it. (no pun intended) That's all I know about it.

SOOOOO now what??? Now that I've gotten over wanting to strangle my PO with his own incorrectly assembled vacuum lines, I'd LOOOOOVE to hear from all of you!!

[J Wikoff]

If either traced line is stock, it's probably the black one, so the white one is likely the boost guage line. I'd unplug one at a time and plug the ends with a vacuum cap (various sizes available at places like Autozone). Then start the car. Which ever one causes your boost gauge to sit at/near 0 at all times is the winner.

Then tap the line into one coming from the blue circle. Bonneville's that came with a boost guage tapped into the line running to the fuel pressure regulator.

The white circle is a vacuum manifold. The blue... I call it a vacuum tree because of the post shape with branches.