Repair And Fix it

Measure the distance from your battery source to the location of the fan. Include in the length any turns or extra footage required for the route. Refer to a wire chart to select the proper gauge and type wire for your project. Marine applications require different considerations than land-based wiring of 12 volt fans.

Disconnect the battery by removing the cable to the positive terminal. Attach one end of the positive wire to the cable that will be reconnected to the positive side of the battery. Attach the other end to the positive connector on the fan. Attach one end of the negative wire to the negative connector on the fan, and attach the other end to a ground location or the negative side of the battery.

Reattach the batterys positive cable to the battery terminal. Test the fan by flipping the on and off switch.

Attach the wires at several locations along the route with wire clips to prevent the wires from chaffing or being damaged later. Place them behind trim to hide them from view.

Mount the voltmeter to your cars dashboard. Use the screws and mounting brackets supplied with your voltmeter. The position of the voltmeter is unimportant, as long as you can mount everything securely and have enough wire if you are not mounting it into a space in the dash that has been set aside for a voltmeter.

Access the wiring harness underneath the dash. This is a bundle of wires that runs down the steering column and into a rectangular connector.

Unplug the wiring harness from the rectangular connector and use a multimeter to find a wire that has power when the key is off, but also does not drop power when the engine starts. To do this, touch the multimeters positive probe to the wire in the harness, and the negative lead to ground, and take note of the voltage measurement. Its best to use the accessory wire or the main power wire. The accessory wire is usually brown and the power wire is usually green or blue, though the colors vary from manufacturer to manufacturer.

Cut the wire approximately four inches away from the connector, between the steering column and the connector. Use a pair of wire strippers to remove approximately an inch of insulation from both sides of the wire.

Attach the voltmeters negative lead to the power wire that is leading toward the steering column and attach the voltmeters positive wire to the power wire leading to the connector. Attach the negative lead of the voltmeter and the power wire to an electrical ground, such as the frame of the vehicle.