Location of fuel shut off switch 89 mustang?

There isn't a readily accessible, easily located fuel shut-off switch on a 1989 Ford Mustang like you might find on some other vehicles. The fuel system relies on the inertia switch (located in the passenger compartment, often under the dash) and the electronic fuel pump control system. If you need to shut off the fuel supply in an emergency, your best bet is to disconnect the negative battery cable.