To find it definitively:
1. Consult your owner's manual: This is the best place to start. The manual should have a diagram showing the location of all relays and fuses.
2. Check the underhood fuse box: This is the most common location. The fuse box cover usually has a diagram showing what each fuse and relay controls. Look for a relay labeled "fuel pump," "EFI," or something similar. Sometimes the diagram uses numbers instead of descriptive labels.
3. Check the interior fuse panel (if necessary): If you can't find it under the hood, the interior fuse panel (often located under the dashboard) might be another possibility, though less common for the fuel pump relay. Again, check the panel's diagram.
4. Use a wiring diagram: If you're comfortable with automotive electrical systems, you can use a wiring diagram for your specific 1989 Pontiac Bonneville to trace the fuel pump circuit and locate the relay. These diagrams are often available online through repair manuals or automotive websites.
Without your specific Bonneville's trim level and options, pinpointing the exact location is impossible. Remember to always disconnect the negative battery terminal before working with electrical components.
