[VetteVet]

Originally Posted by SeanB242

Fusible links confuse me. Is it just a matter of a smaller diameter wire in line of what your booking up. Say I have a 12g wire from alternator to my junction block on my core support. I just put like a 6” piece of 14g wire in there or is there more to it than that?

Fusible links are special wires made of special material that is designed to burn in two slowly, without flaming up and causing a fire. The current surges drawn by starting motors initially, would blow most fast blow glass fuses used in our trucks or the newer blade types used in the later model vehicles.
There is a slow blow fuse called a maxi-fuse that is designed to handle surges that might work as well.
You shouldn't just slap in a short piece of wire unless it's an emergency and not until you've found the cause of the blown fusible link.

Originally Posted by BCOWANWHEELS

You,ve got to have a wire thats able to handle alts. Max output.......

True, 12 gauge was fine on the factory trucks but as the more modern stuff was added the amperage draw is more than it can handle and the alternators
can now generate well over 100 amps. The thing to remember is not what the alternator can output, but how much is the system going to draw. if all the loads are on at once how many amps are being drawn and is the wire large enough to handle that much current.

Most of the time the system is not running full blast, and the thing to remember is that the alternator is not putting out it;s full capacity all the time. A 12 gauge wire would be enough on our trucks if they were stock even with a 200 amp alternator.
A 10 gauge would be plenty and the 8 gauge will handle about anything short of a winch.

Originally Posted by SeanB242

Amps? I assume. And how do I figure that out?

Your alternator amperage max output is hard to determine without an amp meter. and several loads, and You have to know the rated amps of each load and add them all up, then measure the amperage draw with the alternator running at full output. The rated amperage of an alternator is seldom what it's capable of. In other words a 100 amp alternator most likely will not put out a full 100 amps. Advertising plays a role as always.An easy way to tell how much you need is to add up all the fuses in all the circuits and multiply by 80%. Then add in the amperage of the fans and motors and that will give you an idea of the size of the alternator that you need.

In most cases a 100 amp alternator will do. If you are running compressors or a winch then you'll need more. The newer CS alternators a capable of more output especially at idle but remember, a CS 130 or CS 144 is not the amperage output of the alternator the 130 and 144 means the size of the alternator body in mm. AKA the circumference. Converting to one of these is as simple as converting to the internal regulated SI 10 or 12.