To find it:
1. Locate the underhood fuse block: This is usually a large plastic box, often near the battery.
2. Open the fuse block cover: You'll likely find a diagram on the inside of the cover showing the location of the relays and fuses.
3. Consult the diagram: Look for a relay associated with the fuel pump, fuel injection, or possibly even the engine control module (ECM). The diagram should be your best guide. The relay might be labeled with a number, a description, or both.
4. Consider using your owner's manual: The owner's manual for your 1996 Buick LeSabre should have a detailed diagram of the fuse box.
If you can't find it using the diagram, searching online for "1996 Buick LeSabre underhood fuse box diagram" will likely yield a helpful image. Remember to always disconnect the negative battery terminal before working with electrical components.