No fuel guage, wiring help

[Cschafer]

I have a 91 wrecker that the frame has been extended on. The tail light signal is in a junction box just behind the cab. The factory harness was looped up and not being used. The abs was still plugged in but not functional. So to clean up the wiring for the truck I cut off the factory harness just behind were the fuel sender wire t's out of the harness. Now It doesn't work and sits past E like the tank is bone dry. I am assuming that the ground to the sender came from the back of the truck and I cut it off. I was wondering if anybody knew how to wire the sending unit and witch wire is what? I'm assuming I just have to ground one of the wires???

[BobS]

If I'm looking at this correctly the gray/black lead in the harness is grounded. The dark blue/yellow goes to the gauge. The dark green/black goes to the low fuel indicator. If it works backwards, then reverse the dark blue/yellow with the dark green/black as both leads go through the level resistor sensor in the tank.
code: main wire color/tracer color

[Okie Smokie]

I have a '91 that I'm working on. The fuel gauge doesn't work at all most of the time. Every now and then it starts to come up briefly then drops back out again. I know the low fuel light works when the level gets low enough. First off, my wire colors don't match the schematic. I have two gray wires that go to ground, but they're in different locations in the plug than what the schematics show. I have one wire that is blue w/white that's giving me 8 volts. Shouldn't I be getting 12 volts? Where is the hot wire coming from? Fuse panel or gauge? The fourth wire is green w/black and is neutral. I think it should be going back to the gauge, but when I apply voltage to it nothing happens. Please give me some insite as to how it's all supposed to work.

Thanks in advance.