How to Wire a Car Fuse Box

Lead Image
  • 1--3 hours
  • Advanced
  • 10-100
What You'll Need
Wire Brush
Electrical circuit tester
Owner's manual

In many cases, it's useful for you to know how to wire a car fuse box, especially when adding new electrical components to your vehicle. There are 2 main fuse box locations in a car, 1 is plate near the steering wheel; the other is placed under the hood. This is where we’re going to work. The types of wiring in general, are endless because of the different makes of cars having unique wiring systems. This article will only cover what should be the basics for every type of fuse box.

Step 1 - Safety Measures

First of all, take the proper safety measures prior to dealing with your car's electrical system. Disconnect the car fuse box from the battery and be careful with any sharp edges as you can be easily injured. Use a flashlight if necessary.

Step 2 - The Fuse Box

The battery is the main source of power for the car but it needs electrical protection. The fuse box protects the circuits. For example, if you think about the ignition, the defroster or the heater, they all have a fuse designated for them which will burn out if there's any malfunction.

Step 3 - The Wires

Wires provide the means between the system and the car fuse box. It is highly recommended that you use an amperage that is higher than the needs of the accessories you’re going to plug into. The issue here is that, if the wires cover maybe the same or less amperage, they can pull more electrical current causing overheating in the wires. If the accessories pull more power, try to connect them to the battery right into the positive terminal avoiding the fuse box, but be sure to install a proper size fuse in the new wire.

Step 4 - Start The Process

First clean the wires with the wire brush to keep everything clean. The car fuse box is near the battery most of the time. Disconnect the negative battery cable. Unplug the safe box by unclipping it. Depress the locking tab and pull it out. Remove the cover of the fuse box. In the cover, you can see a diagram with all the fuse positions. Here is where you need your owner’s manual to find the exact electrical diagrams needed to put the wires in the right place.

Step 5 - The Wiring

With the little map in the cover and the diagram of the owner's manual, you will have a clear guide on where to plug the wires. To help you out, most wires are color coded, thus giving you more information in how to locate each wire and follow the lead. If the wires are not colored, you must do it the old fashion way. Here is where the tester comes in handy. You will have to test every fuse and wire to make sure of the right numbers, thus giving you the correct lead.

Step 6 - Putting Everything Back Together

Once everything is done, put the car fuse box back and connect it again to the battery. Doing all the wiring process can take you about an hour in average, so be prepared to spend some time without being rushed. The wires and the fuse box can be purchased in any local auto parts store. Remember, if you have any problems that are beyond your abilities call for professional assistance.