73-87 Chevy C10 Gas tank Wiring

I was wondering if anyone knows what color is the wire that is supose to run back to your Fuel tank sending unit on a 78 C10. I removed 3 tanks off my truck when I took it down to the frame and now I'm not sure what wire goes out to the Fuel tank sending unit. Also can I go right off the cluster or does it run threw a relay?

look at the length of you wiring harness and those that are the second longest are most likely for you gas tank and the longest should be tailights, shouldnt be that hard to figure it out

The truck had 3 gas tanks, I removed all the wiring when I tore the truck apart?

come on chevy owners help me out

I NOT SURE ABOUT THE WIRING, BUT I WILL TELL YOU WHAT I DID! I COULDN'T AFFORD A FUEL CELL FOR MY TRUCK AND THE TANK WAS IN MY WAY FOR THE FOUR LINK BARS. SO I WENT TO THE JUNK YARD AND BOUGHT A 3O GALLON BURBAN GAS TANK AND MADE IT FIT (BEHINDE THE AXLE)IN MY SHORT WHEEL BASE 84 TRUCK AND EXTENDED THE WIRING.

purple is the color and its a one wire the other wire goes the the frame for the ground

and it only has power that the cluster because these trucks run off of ohms unless urs is fuel injection