@Sepulvd,
I worked with a guy from your family many, many years ago. He was from Zwolle, LA.
Like my last name, somewhere we're all related. I recognized the spelling. No one else would recognize that name unless you were from Louisiana. You just didn't finish spelling it and I won't do that, I respect your privacy.
Anyway, that wire has to be somewhere down there, the PO wouldn't just rip it out of the bundle. You have the schematic, look and see what color it is and look for that down there. You said something about it, do you have a sending unit in the block, but no wire right? I've got a similar problem the alternator field trigger wire, the one that lights up that red light on the dash when you first start the engine? That's a real important light. It tells you if there are any problems with the alt. The temp. wire to. My old radiator had holes in it and starting out everything was fine and after being gone for about fifteen minutes, I was a block from home and looked down at the gauge and it was 210! It scared me to death but by then I was about a half a block from the house when I saw it. No cracked gaskets though, thank God.
So, yeah, find that wire!