Dash lights help

[Kevinn]

I have 1970 c10 396 bbc 1/2 ton and was trying to figure out why my dash lights dont work and my fuel gauge and I stumbled on this black wire with a blub not connected to anything and was wondering if need to be connected somewhere and if that's the cause why my gauge lights dont work. Also notice this grey wire with something on it dont know its for.I'll appreciate the feedback. P.s I'm new to this its my first car and learning bout this truck.