To find it, you'll need to:
1. Locate the underhood fuse block: This is a plastic box, often black, containing fuses and relays. It's typically near the battery, but it could be elsewhere under the hood. Consult your owner's manual (if you have it) for the exact location of the fuse block.
2. Consult your owner's manual or a wiring diagram: Your owner's manual should have a diagram of the fuse block showing the location of the fuel pump relay. If you don't have the manual, you can find a wiring diagram online (search for "1989 Chevy S10 Blazer 4.3L wiring diagram"). These diagrams will identify the relay by its function or number.
3. Look for a relay with markings: Relays are usually square or rectangular components with markings that may indicate their function (like "FUEL PUMP" or a related abbreviation) or a number corresponding to your wiring diagram.
Without the manual or a wiring diagram, you'll have to carefully examine each relay in the fuse block. If you're unsure, avoid disconnecting or testing any relays until you've positively identified the fuel pump relay. Incorrectly disconnecting a relay could lead to other issues.
