Fuel gauge wiring on 84 C-10

[Spot_remover]

So im wirng up some stewert warner gauges on my truck and im having trouble with the fuel gauge, my shcematic shows 2 tan/white wires for the signal from the sender. But with the tan/white wires it wont register at all. I can hook up other power (dash lights) to the signal wire and i can make the needle move up to 3/4 tank, but i know i only have a quarter tank of gas so its not a signal just the electricity moving it. The old fuel gauge worked.