To stop fuel flow in an emergency, your best bet is to:
* Disconnect the negative battery cable: This will cut power to the entire vehicle, including the fuel pump. This is the quickest and most effective method.
* Locate the fuel pump relay: This relay is part of the vehicle's electrical system and controls the fuel pump. Removing it will prevent the fuel pump from operating. Its location varies by model and trim level. You'll need your owner's manual or an online forum dedicated to 1998 GMC Sierras to find its precise location. The relay itself is usually small and rectangular with several connector pins.
Important Considerations:
* Fire: If there's a fire involving the fuel system, attempting to locate a relay or disconnect the battery may be extremely risky. Your priority in that situation should be evacuation and calling emergency services.
* Professional advice: If you are uncertain about where to find the relay or how to disconnect the battery safely, consult a qualified mechanic or refer to your owner's manual.
In short, there's no readily accessible, dedicated emergency fuel shut-off switch. Disconnecting the battery cable is the fastest and most reliable way to stop fuel flow in a true emergency.
