To find the correct wire, you'll need to:
* Consult a wiring diagram: This is the most reliable method. A wiring diagram specific to your year and model Chevy truck or car will show you the correct wire color and its connection to the fuel sending unit. You can often find these online through sites specializing in automotive repair manuals (like Haynes or Chilton) or via online forums dedicated to your specific vehicle.
* Trace the wires: Carefully trace the wires from the fuel sending unit connector back towards the vehicle's main harness. Look for a wire that goes to the fuel gauge cluster. This is likely the signal wire. Be cautious when working near fuel systems; avoid sparks or open flames.
* Use a multimeter: With the ignition off, you can use a multimeter to test the resistance of wires coming from the fuel sending unit. As the float moves, the resistance will change. This will help you identify the correct wire. Again, safety is paramount when working with electrical systems near fuel.
Without knowing the exact year, make, and model of your vehicle, it's impossible to give you a definitive wire color. Using a wiring diagram is the only reliable way to determine this information.
