The best way to find it is:
1. Consult your owner's manual: This is the most reliable source. It will have a diagram showing the fuse and relay layout.
2. Look for a diagram on the fuse block cover: Often, there's a diagram printed on the inside of the cover itself.
3. Use a multimeter: If you have a multimeter, you can test the relays to identify the fuel pump relay. Remember to disconnect the negative battery terminal before doing this.
4. Online resources: Search online for "1998 Chevy S10 fuel pump relay location" along with your engine type (e.g., "4.3L"). You might find pictures or forum posts that show its location.
Keep in mind: It's often labeled, but not always clearly. It might be labeled simply as "Fuel Pump" or have a more cryptic designation. If you're uncertain, don't just start pulling relays. Incorrectly removing or replacing a relay can cause further problems.