People use a fuel pump relay diagram to locate the control circuit terminals and the power circuit terminals on a fuel pump relay, as eBay explains. This diagram is typically located on the casing of the fuel pump relay.
If a fuel pump relay diagram is not available, the individual needs to look at the relay's mounting base to identify the terminals. The two thinner wires that connect to the relay supply the control circuit terminals, while the two thicker wires supply the power circuit terminal, according to eBay. Once the individual identifies the terminals, he can determine if the fuel pump needs to be replaced by checking the terminals for infinite resistance using an ohmmeter.