To find it, you need to:
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 fuse box under the bonnet: This is the most common location for the fuel pump relay. Look for a diagram on the inside of the fuse box lid that identifies the relays.
3. Check the fuse box inside the car (if applicable): If you can't find it under the bonnet, look for a fuse box inside the car, often located under the dashboard. Again, check the diagram on the inside of the lid.
4. Look for a relay that's labeled: Some relays might be labeled directly as "fuel pump" or have a symbol that indicates their function.
5. Use a wiring diagram: If you have access to a Vauxhall Corsa 1998 wiring diagram, it will precisely show the relay's location. You can often find these online (sometimes for a fee).
Important Note: Before working with any electrical components, always disconnect the negative terminal from your car battery to prevent short circuits.