What colour wire on tachometer 1992 Chevrolet pick up?

There's no single answer to what color wire is used for the tachometer in a 1992 Chevrolet pickup. The wire color can vary depending on the specific engine, trim level, and even the factory's wiring variations during that year. Chevrolet didn't consistently use the same color codes across all their models.

To find the correct wire, you'll need to:

1. Consult a wiring diagram: This is the most reliable method. You can find wiring diagrams specific to your truck's year, make, model, and engine in a repair manual (like a Haynes or Chilton manual) or online (though online sources should be carefully vetted). Look for the diagram related to the instrument cluster or gauge wiring.

2. Use a multimeter: With the ignition on, carefully probe wires at the instrument cluster connector with your multimeter set to the appropriate AC voltage setting (tachometer signals are usually AC). The wire providing a signal that changes with engine RPM is your tachometer wire. Be extremely cautious when working with automotive wiring to avoid short circuits.

3. Check the connector: Sometimes the wire colors are printed directly on the connector itself, although this is not always the case.

Without knowing your specific engine and trim level, providing a color is impossible and could lead to incorrect wiring and damage to your vehicle's electrical system. Always use a wiring diagram to be sure.