Hi everyone,


I've been thinking about doing the dual alternator set up on my truck.


I do some plowing and I need some Amp's at low rpm.


I've heard some diffrent stories from diffrent people that all sound good. Some say that the 2nd alternator dosen't start working till the first one is maxed out on amperage output. Came from Powermaster who reccomend there 200 amp alternator in stock location and move factory alternator to 2nd position.


Another I've talked to said that they both work at the same time and it dosen't matter which goes where because they will put out same amperage till they each reach there max output.


Another has said to keep the 2 alternators the same amp rate. Ex 2-105 amp or 2-145 amp.


Another has said it dosent matter what each one is it will charge to it's max and that's it. Ex 1-105 amp and 1-145 amp.


And exatly what does the little wire that goes from the 2nd alternator to the computer do?


Does it just turn on the alternator at start or does it actually control when the 2nd will kick in?


And if it controls When the alternator kicks in can this wire be bypassed or hotwired to turn on the 2nd right away.


So my main concern is to get a lot of amp's down low in the rpm range. And i'm not sure what the best way of doing it is, my stock alternator is 105 amp. So I could add a 145 amp facory one or I could get the powermaster 200 amp in stock location and forget the 2nd alternator or move my 105 amp to the 2nd position.


Any one know Exactly how our charging systems work on the dual set up?


Thx for any help Diesel Dragon http://www.dieselplace.com/forum/smileys/Cool.gif

I did the upgrade to my 02. Thanks to our web host ~ it was successful. I left the oem where it was and added a 130A I got off ebay for $65. Electrically, position makes no difference. No switching, priorities etc. Just as the batteries are they are in parallel also. That wire, as I recall was for something very minor like to tell the ECM that it is on-line/indicate to the ammeter. Nothing magical ~ if it were I would have made it a point to remember precisely. Its your call ~ I wouldn't waste time w/a couple of 105s as it would be simpler to add a single 200A and not concern oneself w/extra belt, pulleys etc. It seems as if cost is exponential as we move to larger alternators. Me thinks its a market thingy rather than cost/production/value issue.


We don't plow much in CA but FWIW, I did the upgrade to be able to run a large power inverter. Haven't had an occasion to chk it out yet.


Short/sweet ~ size does matter, position/location is inconsequential


Edited by: ShumDit