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absolutely - these are all short runs, even that one is likely less than 4 feet. 4 gauge for the "magic three" is appropriate even for a guy who might have an alternator upgrade and is wildly taxing a 1/0 main power cable, because of the short length.

Same reason you can get away with an 8 gauge ground wire if it's just a foot or so, even on a monster SPL amp.

there is more to it than just that geo almost every alt company reccomends 4ga on there alts because if you use 1/0 the resistance is to low and the post on the alternator actually heats up and can cause internal issues on the alt.

Bwcad1 wrote:there is more to it than just that geo almost every alt company reccomends 4ga on there alts because if you use 1/0 the resistance is to low and the post on the alternator actually heats up and can cause internal issues on the alt.

WHAT??????

I am not saying I don't beleive you.

BUT

Your talking alot of resistance, and alot of heat if they expect you to run small enough wire to cut the output of the alternator.

Keep in mind, heat is a product of resistance. The higher the resistance the hotter things are going to get.

AND

If heat is an issue at the post, smaller wire and higher resistance will make that worse. The larger wire will give you a LARGER area to disapate the heat. Having a smaller wire, and EXPECTING it to heat up (in the form of resistance) will only make those problems worse.

[quote="geolemon"]absolutely - these are all short runs, even that one is likely less than 4 feet. 4 gauge for the "magic three" is appropriate even for a guy who might have an alternator upgrade and is wildly taxing a 1/0 main power cable, because of the short length.

Same reason you can get away with an 8 gauge ground wire if it's just a foot or so, even on a monster SPL amp. ]


Love the avatar by the way :)

Chris from Washington wrote:Love the avatar by the way :)

That is a cool avatar :)

I've been teaching myself how DC electronics work (slowly but surely :) ) and they say that you should disregard the resistance in wire because it's so small that it's negligable.

JeremyC wrote:WHAT??????
I am not saying I don't beleive you.
BUT
Your talking alot of resistance, and alot of heat if they expect you to run small enough wire to cut the output of the alternator.
Keep in mind, heat is a product of resistance. The higher the resistance the hotter things are going to get.
AND
If heat is an issue at the post, smaller wire and higher resistance will make that worse. The larger wire will give you a LARGER area to disapate the heat. Having a smaller wire, and EXPECTING it to heat up (in the form of resistance) will only make those problems worse.

don't argue with me argue with them. the way i understand it is like this. the smaller wire has a higher resistance than the post so the heat builds up accross the entire length of the 4ga not just the little 1 inch post. and there not expecting you to cut the resistance of the alternator i dont know where that came from. also dont forget just like geo said wire gage depends on length on top of that your alternator isnt always producing 200-300 amps. 4ga is perfectly fine.

solacedagony wrote:That is a cool avatar :)
I've been teaching myself how DC electronics work (slowly but surely :) ) and they say that you should disregard the resistance in wire because it's so small that it's negligable.

in most instances this is correct but when your talking about high current applications it changes greatly

"We have found ways to keep resistance lower at areas like that and suggest at least 4 GA and prefer 2 GA or 0 GA."
That's a quote from H-O-Alts-Rick.
Disclaimer: No clue who he is, who he works for, or what his knowledge of alts is. lol

Seems like from his response that it depends on the parts (or design?) of the alt that could potentially make this a problem.

I agree 4 guage is enough. Thats what I always use, I just felt their reasons were a little weird.