Where is the fuel cut off switch located on a 1989 Ford Ranger with 2.8 v6?

There isn't a readily accessible, dedicated fuel cut-off switch on a 1989 Ford Ranger 2.8L V6 like you might find on some heavier equipment or race cars. The fuel system relies on the ignition system and other safety features to shut down fuel delivery in the event of a crash or other malfunction.

To stop the fuel flow, you'd need to disable the ignition system (turning the key to "off") or disconnect the power to the fuel pump (which is usually located in the fuel tank and requires dropping the tank to access). Neither is a simple "switch" solution.

Important Note: Disconnecting the fuel pump relay (a safer alternative than messing with the tank) is possible, but requires finding the relay, knowing which one it is (consult a wiring diagram), and understanding the associated risks. Improperly disconnecting electrical components can damage your vehicle's electrical system.