Wire (not wiring) information

[Uncle Skip]

From the other fourm.
Wiring gauges and amperage loads for common automotive wires.

Given the fact that I"m going to rewire Nadine, I have absolutely no experience or expertise in electrical stuff (face it, electricity really is magic... the only reason it works is because we believe it will) I did some searching today for the load rating for various gauges of wires.
What I found was not what I expected.
On 12 volt systems (excluding really long runs of wire) the information shows the wires carry a lot more amperage than I expected.
And, bear in mind that most of our stock trucks run on less than 80 amps from the alternator to power everything in the truck.
Mine has a 130 amp 1 wire but even with all the extras I have, I doubt that I'm pulling anywhere near that under normal operation.

Constant use circuits might require one size bigger if you're at or close to the load rating. IE...... if your headlight circuit is pulling a full 20 amps and you have 16 gauge wire, you might want to go one size bigger and use 14 gauge wire.
(20 gauge is not good for much except maybe dash lights and such. Most every thing else is 18 gauge or bigger. I'm using it for my tach trigger and dash lights but thats about it.)
So, here is a "general" load rating for automotive wires.

20 ga. 8 amps
18 ga. 10 amps
16 ga. 20 amps
14 ga. 40 amps
12 ga. 60 amps
10 ga. 100 amps
8 ga. 150 amps (this one is a big mammy jammer wire and I doubt you'd use this unless you have one of those ghetto, sonic powered, ear shattering, glass breaking stereo systems, and then you'd wire it seperate from the rest of the truck.......)

If you're nervous about primary load, just run two 10 ga. wires to seperate terminals and split it up.
Just remember to use the proper fuse for your particular circuit use and you should be fine.
Hope this helps.
U@ss