How to Wire a 12 Volt Fan

by Ed English

Wiring a 12 volt fan is possible in any environment were 12 volt batteries are the power source. Whether a boat, automobile or house battery bank is the power source, the methods are the same for wiring a fan or any other of a long list of 12 volt appliances. Only two wires, a positive and a negative, are necessary. Properly sized wire is also necessary to control the voltage drop from the fan to the power source.

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 battery's 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.


  • check Install a 12 volt receptacle and plug in the fan if it has a 12 volt plug.
  • check Add a wire to a bus bar from each side of the battery terminals to easily connect several 12 volt devices.
  • check Wiring the fan on a separate circuit by itself will avoid overloading an existing circuit.
  • check If the fan does not contain a fuse, an inline fuse must be installed in the positive wire.


  • close Take safety precautions and wear proper safety equipment while using hand tools.

Items you will need

About the Author

Ed English began his writing career with his first book titled "SCUBA Diving A Newcomer's Point of View" published in 2005. English has owned businesses for over 25 years; he holds several certifications from the National Cable Television Institute, Professional Association of Diving Instructors, American Sailing Association and a Home Inspector Certification.

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