alternator upgrade

[chevyhed53]

I'm getting ready to add some accessories to my barebones '56--nothing dramatic, some tunes, upgraded lighting--and I'm swapping my old 55 amp alternator for a 100 amp unit. The wire from the alternator to the starter is no bigger than 10 gauge, and I've been told I need to run a larger wire with a bigger alternator. I've got a roll of some very nice 4 gauge wire sitting on a shelf. Is that too big? Is it possible for main power wire to be too big??
Thanks!

[SCHRUMGMC]

How can you wire an alternator where the idiot light will go off when you start the truck up and come on when you turn the key

[OrrieG]

I would recommend you start with the attached link to made electrical, they have a really go handle on this kind of stuff. I know my EZ wire kit included a jumper wire for use with a larger alternator but it was not #4, maybe someone else can chime in, my ez wire box is buried at the moment.
http://www.madelectrical.com/electri...hreewire.shtml

[Stepside Jim]

My Painless kit added an 8 gauge wire for when you go to 100 amp.

[mr48chev]

I'd think 8 would be more than sufficient. Larger won't hurt anything. The alternator is only going to put out as many amps as your system asks for at a particular time.

Figure that if right after you start up and head out it has to recharge the battery back to where it was before you started the engine, power the sound system if you have one, power the ac, On occasion supply power for the electric windows, seat or heated seats. power the headlights and other lights if they are on. Seldom if ever would you be using all at the same time.

Two add ons that we tend to put on trucks tend to draw extra power and that is high powered headlights or extra high powered off road or driving lights and big sound systems.

[chevyhed53]

Thanks all for the responses. Lights and tunes are about all I'm going to do

[Coupeguy2001]

You might think of getting a larger ring terminal, crimping two 10 gauge wires in it, and running them together to the alternator, That way, they will handle more amps, and be as flexible and unobtrusive as a single 10 gauge wire.
IT looks just a little different than one wire in the terminal, but cleans it up when you run two wires the same length together.
If in the future, you use an electric fan, or install AC, your wires are big enough to handle the load.
Also, you might install an electric buss on maybe a 1/4 " piece of micarta under the dash. the wire being connected under the dash will make the runs shorter, and not require larger wire,, giving you a place to run a fuse panel to to run the extra accessories you want to install.
I would definitely make the wire bigger, because if you ever have a dead battery, it will take the full 100 amps for about a minute till the battery voltage comes up.
you could fry the main wire and the ones resting on it

[Coupeguy2001]

You might think of getting a larger ring terminal, crimping two 10 gauge wires in it, and running them together to the alternator, That way, they will handle more amps, and be as flexible and unobtrusive as a single 10 gauge wire.
IT looks just a little different than one wire in the terminal, but cleans it up when you run two wires the same length together.
If in the future, you use an electric fan, or install AC, your wires are big enough to handle the load.
Also, you might install an electric buss on maybe a 1/4 " piece of micarta under the dash. the wire being connected under the dash will make the runs shorter, and not require larger wire,, giving you a place to run a fuse panel to to run the extra accessories you want to install.
I would definitely make the wire bigger, because if you ever have a dead battery, it will take the full 100 amps for about a minute till the battery voltage comes up.
you could fry the main wire and the ones resting on it

[chevyhed53]

Thanks for the suggestions! I actually ran a 4-gauge wire from the starter to the alternator, with a bigger ring terminal. And I like the idea of an auxiliary fuse box under the dash.