To find it, you need a multi-pronged approach:
1. Consult your owner's manual: This is your first stop. The manual *should* have a fuse box diagram showing relay locations. Even if it doesn't specifically label a "fuel pump relay," it might list relays by function (like "engine control" or something similar that could indicate the fuel pump relay).
2. Check the underhood fuse box: This is the most likely location. The fuse box usually has a cover with a diagram printed on the inside. Look carefully at this diagram; it might show relays by function or number. Some relays might be labeled, but often they aren't. You'll likely have to trace wiring if the diagram doesn't provide a clue.
3. Use a wiring diagram: A wiring diagram for a 1993 Camaro Z28 is crucial. You can find these diagrams online (through sites selling repair manuals or dedicated automotive websites) or in a Haynes/Chilton repair manual. The diagram will show the fuel pump's circuit and trace the wire back to identify the correct relay. This is the most reliable method.
4. Look for a relay with a similar amperage rating: Fuel pump relays usually handle a significant amount of current (high amperage). Compare the amperage ratings on the various relays in your fuse boxes. A relay with a substantially higher rating than others is a likely candidate.
5. Process of elimination (with caution!): If you have a multimeter, you could try testing relays one by one, but be extremely careful not to short anything or cause damage. This method is only recommended if you're experienced with automotive electrical systems. A mis-step here can easily damage your car's electronics.
Important Safety Note: Always disconnect the negative terminal of your battery before working with any electrical components in your car. This prevents accidental short circuits and protects you from injury.
In short, there's no shortcut; you'll need either the owner's manual, a wiring diagram, or a combination of careful observation and (if experienced) multimeter testing to locate the fuel pump relay. The wiring diagram is your best bet for a definitive answer.
