Wiring Basics – Wire

At some point a Jeeper decides to install a new gadget or modify an electrical component.  Often these electrical items are a CB radio, auxillary lights, or a piece of audio equipment..the list goes on.  So many times we see poor wiring techniques it’s amazing there isn’t more failures and fires.  In this section we are going to discuss wire.

WireRack

Wire

Wire seems simple enough but not all wire is created equal.  Wire thickness or gauge is important to ensure the wire can handle the current needs of the circuit.  Additionally, wire length will have an impact on the wire’s ability to carry current.  Heavier gauge wire can supply larger current amounts and not overload the wire.  Too much current through a wire will cause the wire to overhead and possibly start a fire.

Reference the table below for help with wire gauge to length.

Wire Gauge Selection Table 12 Volt Circuit

AMPS 3′ 5′ 7′ 10′ 15′ 20′ 25′
0 to 5 18 18 18 18 18 18 18
6 18 18 18 18 18 18 18
7 18 18 18 18 18 18 18
8 18 18 18 18 18 16 16
10 18 18 18 18 16 16 16
11 18 18 18 18 16 16 14
12 18 18 18 18 16 16 14
15 18 18 18 18 14 14 12
18 18 18 16 16 14 14 12
20 18 18 16 16 14 12 10
22 18 18 16 16 12 12 10
24 18 18 16 16 12 12 10
30 18 16 16 14 10 10 10
40 18 16 14 12 10 10 8
50 16 14 12 12 10 10 8
100 12 12 10 10 6 6 4
150 10 10 8 8 4 4

2

200 10 8 8 6 4 4 2

When connecting wires together always use the same or higher gauge wire.

Insulation

In addition to gauge wire insulation can vary.  Choosing the proper insulation type for your application is important.  Wiring that will be run under a Jeep’s hood should be rated for the temperatures that will be experienced.  Most automotive wiring is capable of handling these temperatures.

Wire insulation thickness can vary, don’t judge a wire’s gauge based upon the insulation..cut the wire and inspect the wire to determine gauge.

Colors

Wire can be had in an assortment of color which can make for a clean easy to follow wiring job.  The only colors that should always be kept standard are black and red.  These two universally stand for positive (red) and negative/ground (black).  Ground rarely uses colors and is typically always black.

Stranded vs Solid

Solid-Conductor-Insulated-Single-Core-Wire

Using solid wire in an automotive application is a no no.  Especially house type wire.  Stranded wire can deal with vibration and movement experienced in vehicles.  Solid wire is difficult to work with and will fatigue from movement over time.

Next – Connectors