How to Reset an Inertia Switch

A fuel inertia switch is also known as a fuel cut-off switch. The inertia switch is designed to cut off the fuel supply to the engine. Once the inertia switch senses a heavy vibration or abnormal vehicle movement, the switch will disable the supply of fuel from the fuel pump to the engine. Once the inertia switch has been tripped, it will require resetting to properly function again. The switch can be reset using the button on the front portion of the switch.

Things You'll Need

• Owner's manual

Instructions

1. Locate the inertia switch using to the vehicle's owner's manual. Some inertia switches can be found under the passenger-side dash or behind the seat. The switch resembles a small, black, square box.

2. Locate the "reset" button on the front of the inertia switch. Press inward on the reset button for 15 seconds. Release the switch.

3. Turn the ignition key to the accessory position for five seconds, and then turn it back off. Repeat this three times. Crank the engine on the fourth turn.

4. Allow the engine to run for about a minute so the fuel pump can refill the fuel lines. Turn the engine off.

Tips & Warnings

• The inertia switch acts as a safety switch in case the vehicle is involved in an accident. Once the switch detects the sudden motion from the accident, the switch shuts off the fuel supply to the engine to prevent a fire from starting from the exposed fuel.

• Never smoke or use open flames around any type of fuel or fuel components.

References

• " Ford Ranger and Mazda Pick-ups Haynes Repair Manual covering all Ford Ranger models for 1993 thru 2010 and Mazda B2300/B2500/B3000/B4000 for 1994 thru 2009;" John Haynes; 2010