Diagnosing Fuel Relay in a 1994 Chevrolet 1500
From time to time, the 1994 Chevrolet 1500 fuel relay system may show different problems. Usually, these troubles can be removed with some simple diagnosis techniques. Remember to wear protective gear and keep a class B fire extinguisher nearby when you carry out the troubleshooting process.
The fuel relay is located on the passenger side fire wall, “near the top of the compartment under the relay cover,” according Haynes manuals. Mounted about 6 inches to the right of the fuel pump fuse, it’s black with five wires coming out of the bottom.
Examine fuel lines for a leak or crimped hose (or fuel line) impeding the flow of fuel to the carburetor. Have someone turn the ignition on while you listen for the fuel pump (located in the fuel tank) to activate. A whirring sound can be heard for approximately two seconds when the fuel pump is working properly. If there is no sound, turn the ignition off and remove the cover from the underhood fuse/relay center. Using the guide printed under the cover, locate the fuel pump relay fuse. Examine it for usability. Replace if the element is broken.
Next, test for electrical current by performing a voltage check. If the fuses and relay are good, check the fuel pump relay control circuit from the relay to the engine control module/powertrain control module (ECM/PCM). If the circuit is good, have the ECM/PCM diagnosed and serviced by an authorized repair shop or dealership.