How to Wire a Power Outlet for a Car
- 1). Mount the plug and fuse box in their permanent locations temporarily and determine the length of wire needed to get from the plug to the fuse box and from the fuse box to the battery.
- 2). Connect one end of the red wire to the positive terminal on the plug. Run the other end back to the new fuse box and connect it to the first of two wire connections on the back of the fuse box. Each fuse slot has two wire connections on the back of the fuse box. Make sure to run the wire so that it is not in the way of anything.
- 3). Connect one end of the black wire to the negative terminal of the plug. Connect the other end of the black wire to a metal part of the car frame. The car frame is the best ground source.
- 4). Connect one end of a second red wire to the second wire connection on the back of the new fuse box. Drill a hole through the firewall to get access to the engine bay. The size of the hole is governed by the size grommet used. Once you choose the grommet, the instructions will dictate the size hole needed.
- 5). Insert the grommet, and push the other end of the red wire through the grommet to reach the battery. Connect the end of the red wire to the positive terminal of the battery.
- 6). Test the new plug's operation.