how to properly wire 2 alternators

[slowfkncar]

How much power are you pulling? With 200 amps you could get away with 3000+wrms if your using ONE alternator wired to a rear bank of 300+ah.

[Saltine]

right now its some old sundown 1500 v1s 2 wired at .5ohm, a 100x4 and 125x2 sundown...but im upgrading and have a sundown NS-1 6500watts

[Colin - STAPUFT]

I did this with my Astro, but I had to remove the compressor (lucky you- I know how hot it gets in NO). Instead of buying HO Alts from one of the companies everyone knows, I rebuilt two factory alts with stronger internals and put them in. Something more fun about doing it yourself- that is all.

It is somewhere in my build log (link can be found in my signature- maybe pg 24 or so?), but in short- I simply tapped into the factory harness for the sense wire and whatnot. Then I wired those to the second alternator. Then the first and second alternator are both wired (charging wire) to the battery separately (fuses between the battery and the alternator).

They won't "fight" each other. What happens is this: if one is slightly weaker, has a different charging curve, charges at a bit higher or lower voltage- then one will do the majority of the work- Up until a certain point. When you crank the stereo or give any demand that drops your charge to or below the amount that that "weaker" (not the right word- but whatever) alternator will really start kicking in. In actuality, if the two alts are the same then you won't really ever notice that one may be stronger. This is one of those situations where the theory is getting in the way of practice. lol

Hope this helps.

[Purplehaze]

ok, thats what im looking to do then...on the isolator though I was told that since the battery under the hood was close to the alternator (short wire) and the four in the back were so far away that the under hood battery would be getting most of the charge, so hooking an isolator up would help in distribute the charge evenly to all the batteries

You don't need an isolator, don't waste your time and money on it. I'd just forget about it.

It has been proven many times they are not good for what we do (car audio)...

I would just listen to Alpine and Colin, they know what they are talking about 4 - sure.

[Saltine]

thats why i was checking before diving in to this...so now i just need to get some fuses and some more power wire and get to fabbing up my brackets...