At times it is practical and economical to directly wire an electric fuel pump. The need usually arises when the fuel pump drive circuit inside of the main computer fails, yet all the other computer circuits are good. In this case, the main computer ground signal going to the fuel pump relay is defective. By simulating the ground signal with a simple, dash-mounted toggle switch, the repair is a fraction of the cost of replacing the computer.
Drill a 1/2-inch hole in an unobtrusive location under the drivers-side dashboard. Mount a toggle switch and tighten the retainer nut with a wrench.
Use a wire-crimp tool to create a short wire that will connect one end of the wire to one side of the switch, and the other end of the wire to a clean, paint-free section of metal. Look for a good location that has a sheet-metal screw going into bare metal. Loosen the screw and install the wire connector, then tighten the screw and complete the new ground circuit.
Raise the hood of the car and locate the electrical power center. Lift open the power-center cover and locate the fuel pump relay. Fuse and relay locations are often printed on the inside of the cover. Reference a service manual and locate the pin number and wire color-code that comes from the engine computer to the realy. Locate this wire in the nearby wiring harness that goes to the power center.
Cut the wire with the wire crimp tool and crimp a new wire onto the section that goes to the relay. Run the wire from the wiring harness to inside the car. Locate an area to run the wire through the firewall, but be careful that the wire will not abrade on sharp metal edges as it enters the car.
Connect the wire to the empty toggle switch connection. Turn the toggle switch on and start the car. If the wiring was installed correctly, the car will start. If the car fails to start, be certain that the selected wire located at the power center is correct.
