Wire Size Calculator
Selecting the correct size of wire or cable when installing accessories is an exacting science. Too small and the result is a large voltage drop and high heat from the wore or cable. High load accessories such compressors or high powered driving lights are particularly demanding and incorrect cable selection can result in fire damage to the vehicle if too small a cable is used.
The guide below should be used to obtain a voltage drop of no more than 0.5V in a 12 V system or 1.0 V in a 24 V system. Also the cable length must include both positive and negative cables. Also, when connecting high load accessories, a separate earth cable should be run to the power source. Do not rely on the vehicle body for ground as this can result in damage to other elctrical equipment in the vehicle.