Before & After - My 1993 K1500

[93 Krawler]

Originally Posted by underpowered

when dealing with electric, bigger is always better. especially when dealing with DC. also, if it is a sustained load you want to go bigger as well. No way i would run 125 amps through 10g wire. chances are you are not sustained amps, so any of your individual breakers should trip before you hit full current pull


I know industrial wiring, 10g is 30 amp wire, for 125 we use 2awg. granted this is 120-480v vs 12v, but an amp is an amp no matter the voltage. If it were mine, i'd use no less than 6awg on a feed such as that.

I know what you mean, I have 2/0 for my battery cables.

My factory battery cable was like #2-4, and there was a #6 that ran everything but the starter. I think the charge wire is a #8. If you add all the power wires that come out of the loom on the 5.3, I'd say they are about the size of a #8 max. I don't even see how a 18g wire can handle 10-15 amps. DC is confusing as far as loads.

In a house panel, the breakers add up to more than the the service size. Does the same apply to DC. If you add all the fuses in any car, I bet it adds up to more that the battery cable size. I guess wattage plays in there somewhere. Like high power car amps. they take huge wires.

I'm with you, go big. I'm getting a 150 amp relay, and run a #4 to it. If that's not enough, then I give up.