Need help identiying wire on '81 Chevy Silverado

[mhoflin]

I have a 1981 Chevy Silverado C10 and I am trying to restore as much as possible. I cannot figure out what a shielded wire I found on the passenger side of engine compartment goes to. It does not have a typical connector on the end, it seems to be some sort of "metal block" and it runs down the passenger side but I cannot determine what it is.

As I stated before it is shielded, kind of like a "coax" but smaller. I really need some help here. Does anyone know of this wire and where it connects to?

Thanks so much!