I found these three wires cut with butt connectors on them. I don't know what the little black box is but I'm guessing it has to do with boost/vacuum with that line running off of it. I just wanted to know what the wires were for?

 

Looks like a boost sensor for an electronic boost gauge. Guessing they mounted it in the engine bay and then lengthened the wires and that's what the butt connectors are from.

 

^ this

Black box is the boost sensor from an electronic boost gauge. Seems like the last owner was in a hurry when they got rid of the car to only take the gauge portion with them and not the sensor.

 

That makes no sense