How to Change Auto Light Bulbs From 6 to 12 Volt

Some early model cars were equipped with 6-volt lighting systems. Converting to a 12-volt system requires checking the size of the existing wire feeding the lights. If the wire can handle the additional current, it won't have to be replaced. The wire size and maximum voltage allowed are both written on the insulation part of the wire. Most automotive wire sizes range from 18 to 8 with 18 the smallest.

• 1

  Disconnect the battery's negative black cable, and locate the lights you are planning to replace. Check the wire size. Most 6-volt wiring can handle an increase to 12 volts; you'll only have to change the light bulb sockets and the fuses at the fuse box. The fuse box is usually located below the left side of the steering wheel.

• 2

  Remove the light bulb and the light bulb socket. Cut the socket off and set it aside. Strip 1/2-inch of insulation off of the ends of the remaining two wires. Connect the positive wire to the positive wire of the new 12-volt light socket, then connect the negative wire to the negative wire of the socket. Positive wires are usually red and negative wires are usually black. If other colors are used, the negative wire will be a solid color and the positive wire will be the same color with a white stripe.

• 3

  Seal each splice so that it is air- and water-tight using a splice sealing kit. Connect the light bulb to the socket and secure the light in the light bulb holder.

• 4

  Check the light bulb information to determine how much current the bulbs require. Replace the existing fuse at the fuse box with a higher rated fuse based on need. Turn the lights on to test them.