Alternator Wire Gauge Size Chart

Alternator
 

Any time you upgrade your alternator, you should also strongly consider upgrading the gauge (size) of the wire that charges the battery as well as the fusible link in case of a short.

The chart below charts the gauge wire required based on alternator amperage output and length of wire.

Alternator Output (Amps)Up to 4 ft4 – 7 ft7 – 10 ft10 – 13 ft13 – 16 ft
20 or less 14 12 12 10 10
20-35 12 10 8 8 6
35-50 10 8 8 6 6
50-65 8 8 6 4 4
65-85 6 6 4 4 2
85-105 6 6 4 2 2
105-125 4 4 4 2 2
125-150 2 2 2 2 0