ok guys, i cant figure out what this is and dont wanna put my intake manifold on until i do. picture this. looking at the top of the block, with the IM off, you see the long black (oil sensor?), and below it the steam pipe. right in the middle is where i can see my wiring harness split into 4 ways (like a cross). well at one of the splits, there is a small black wire leading to some sort of bolt looking thing, with a hole, and threads around the hole. kind of like this
--I--(4 way harness split)
-- \_o(wire coming from harness connected to (bolt?) any ideas??
(ignore these 2 lines)

 

Take a picture if you can.

 

Sounds like the vacume line for the heater controls. Is it hard plastic? Pics would help ALOT...