* Under the hood in the fuse box: This is the most likely location. The fuse box is usually located near the battery. Look inside the fuse box for a relay that's labeled "fuel pump" or has a diagram showing a fuel pump symbol. The relay itself might be a standard automotive relay or part of a larger panel with other relays.
* Under the dash: Less common, but possible. Check your owner's manual or a wiring diagram specific to your truck's year, make, model, and engine.
To find it more precisely:
1. Consult your owner's manual: This is the best place to start. The manual should have a diagram of your fuse box and relay locations.
2. Use a wiring diagram: You can find wiring diagrams online through sites specializing in automotive repair information (some may require a subscription). These diagrams will show the relay's exact location and sometimes its color coding.
3. Check online forums: Search online forums dedicated to 1989 Chevy trucks. Other owners might have already identified the location of their fuel pump relay and posted pictures or descriptions.
Remember to always disconnect the negative battery terminal before working with electrical components to prevent shorts and potential injury.
