# Aux Alternator For Duramax



## intlco (Nov 15, 2004)

Has any installed a second Alternator in a Duramax?

I've got the 2004 Duramax, and I don't think that 1 alternator that's only 105 amps can handle plow and dump operation given the conditions out here.
The temps being below zero now has really taken a toll on the batteries and I don't even have the blade on yet.

I went to the GM dealer, but the service guys didn't know S**t about doing it, and they didn't even know where to get the kit.
Svc mgr comes out and says, it is normal for the d-max battery guage to be red lined negitive during the first 10 minues of running after startup.

Then I asked, can you get bigger batteries, he says, I Don't Know! We haven't doné anything with batteries yet. Maybe you should find someone who has do this and ask them.
I think anything beyond writing a work order if a difficult project for Chevy/GMC dealers.
Can't wait till someone makes a service manual for the d-max.


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## Tarkus (Nov 19, 2004)

I do not have a diesel but I do have a 105 amp alt on a GM truck that has plowed for about 5 years and still on original dual batteries. You biggest problem is glow plug/preheat draw. You might look in to mounting a few amp trickle charger in your truck to keep battires topped off between runs. I had one plow truck for years with only a 70 amp alt and no problems other than batteries not lasting more than 2 or 3 years tops.


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## cet (Oct 2, 2004)

Plug the truck in. It is brand new and unless your first job is as soon as you get out of the driveway you will be a full juice within the first mile. What is the exact set up you are trying to run?


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## CHPL (Oct 26, 2003)

*dual alts*

check here
http://www.gmdieseltech.com/store2/cart.php?target=category&action=view&category_id=279


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## jimsmowin (Jul 28, 2000)

i have the 6.5 my alternator went about three to four years later went to an alternator starter rebuild guy now have 180amps plus cost alittle over 1.00 per amp $200 and change. dual batteries and 180 amps no promblems on 1ton dump my hydraulic pump is engine mounted and electrically engauged


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## MickiRig1 (Dec 5, 2003)

An automotive electrical shop should be able to help you out. Call one that rebuilds components. They can rebuild your stock alternator for about a $1 an amp if you bring it to them. You then re-install. If space is not a problem you could go to a big dog ambulance type alternator 150 amps. But you would have to upgrade wiring and isolator setup for the batteries. You could also then add toys like an on board arc welder or power a house when the electrics out.
Keep in mind that it will only put out around 1/3 of it's rated output at low RPM. But it will help the batteries to recover faster then the stock system.


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## calhoun (Oct 18, 2003)

If you got the plow prep option you get a 145 amp alternator. 
A dual alternator is also a factory option. The parts department should be able to fix you up with a factory setup.


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## Tarkus (Nov 19, 2004)

calhoun said:


> If you got the plow prep option you get a 145 amp alternator.
> A dual alternator is also a factory option. The parts department should be able to fix you up with a factory setup.


Again you do not "need" it and it would be pricey to buy factory upgrades of questionable need over counter too. ALso when you increase alt size you have to watch the size of the buss in truck to handle higher alt current. I have seen much larger alt put is some truck smoke a few wires under heavy load so be careful with the size of any increase if you elect one. Years ago I plowed with a 70amp alt with no problem other than single battery just lasting a few years so every few years I would get another battery for 40 bucks or so at WalMart or Sams and never touched alt itself for over 15 years too.


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## calhoun (Oct 18, 2003)

I think everyone has there own idea of "need".

I am assuming an electric plow.
Lit up at night, Sub zero, lots of short pushes requiring lots of pump cycles, spreader running, radio, heater, wipers. I remember plowing about 10 years ago with a 80 amp alternator thinking I didn't need anything bigger. When the lights got dim and the pump slowed I just had to stop, in the middle of some jobs, and run the truck with everything off to keep everything charged.

I had engine driven hydraulics on another truck and I would agree you don't "need" more electric power. Does anyone still offer engine drivin pumps?


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## intlco (Nov 15, 2004)

COnsidering the tempertures here are below zero at night, it is almost impossible to keep the batteries at full power.
In the past, we've used all Chevys with the 454, and we destroyed all of the 105 alternators in the first month of plowing, the just burned up from over working. Then I'd just replace them with the 130amp and had no problems. But also, on the old trucks, the dump body was belt driven.

This new truck is set up of couse with the d-max, and the dump body is electric stahl hoist. Just hoisting the dump with a heavy load of snow plays hard on the batteries. I can just imagine what the plow will do.
The truck does not have plow prep pkg, because it was not an option on a crew cab w/diesel engine.

We don't have any automotive shops for alternators in my rural city. And the dealer don't know anything. The dealer is going to be installing his first aux alternator monday on some ranchers truck he told me. But they told me that the rancher is providing all parts, so they don't know where he got them.


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## MickiRig1 (Dec 5, 2003)

*intlco*:

Try :Summitracing.com / 1-800-230-3030 Akron Ohio Area
They do mail order / next day.

They have 200 amp units listed for Chevy's in my new catalog
But they only list to 02 trucks.

Or get some 4x4 magazines or "Sport Truck" <--- Mostly just ads for products
The off road guys are always upgrading their charging for just what we do, low speed heavy amp draw / winch's / welders / compressors, etc.
Might consider "Battery Blankets" (heaters) if they are warm they put out the rated reserve.
Just remember you have to upgrade the output wires to the batteries and the isolator setup so it does not fry under heavy amp flow.


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## Tarkus (Nov 19, 2004)

A heated battery blanket will help a batteries cold starting (I use one on a old farm tractor) but they will not add any reserve capacity when running because the batteries do heat some from charging and discharging in snow plow use and in theory they could actually cause a battery to possibly get too warm if it is being worked hard in mild temps because blanket would hold the heat in it even when not powered itself.


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## gearhead (Nov 30, 2004)

intlco said:


> Has any installed a second Alternator in a Duramax?
> 
> I've got the 2004 Duramax, and I don't think that 1 alternator that's only 105 amps can handle plow and dump operation given the conditions out here.
> The temps being below zero now has really taken a toll on the batteries and I don't even have the blade on yet.
> ...


look here for daul alternator kits
http://www.gmdieseltech.com/store2/cart.php?target=category&action=view&category_id=279


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## extremsnomobile (Dec 3, 2004)

nobody knows anything about a durmax at any repare shop unless teh guy has one so sorry. i work for teh town aux fd. and we run one deisel and its on a trickle charge constly fromt eh time it pulls in to teh time it leaves.


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## 4evergreenlawns (Oct 22, 2002)

That GM Diesel site is cool. Now anyone know a source of supply for dual Alt kit of Gas application??

I have a 01 2500HD 6.0 Gasser with daul Batteries but would like to all the second Alt if a bolt on kit is available that would be great. 

Currently running a H/O 170AMP Alt. but with the little pully on there is give out very LOW amps/volts at idle. Give it about 1000 RPMs and it puts out like a girl at a home comming dance. I want something more steady. 

Thanks.


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## Tarkus (Nov 19, 2004)

4evergreenlawns said:


> That GM Diesel site is cool. Now anyone know a source of supply for dual Alt kit of Gas application??
> 
> I have a 01 2500HD 6.0 Gasser with daul Batteries but would like to all the second Alt if a bolt on kit is available that would be great.
> 
> ...


You want to find a aftermarket alt that has a lot larger stator and rotor diameter if low speed output is your goal.


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## 4evergreenlawns (Oct 22, 2002)

All I know is I call the guy that builds the Alt and I get what he sends me. I do know that I am not happy with that I have. I get the long story about having the smaller pully to get the higher AMPs. When I ask what effect will the higher RPM have on long sustained trips such as highway driving? I was told NO PROBLEM. I have burnt up two rectifiers so far and I do not think this is the ALT for my application. 

I have Dual Alts on my 05 F-350 PSD and after two plowable events with ALL ELECTRIC plow,dump insert, electric tailgate spreader, light bar, heater, wippers, and so on I am very happy with the performance. No dimming of lights, plow, dump insert and spreader all work at normal speeds even when I am using them in combo. 

So therefore, when I see the dual atl kits for duramax I just would think the bolt on kit MUST be available for the GAS application too.


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## Tarkus (Nov 19, 2004)

There are two ways to get more current out of a alt at low speeds. One is to increase the speed of alt at a idle and the other is to increase the lines of magnetic flux and their strenght so that more output is induced per RPM. You can increase the amount of winding on the stator and armature but only to a point where as increasing the diameter of these parts yields far better returns. For what it is worth.


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## ratlover (May 5, 2003)

give the guy at that gmdiesel tech site a call. His name is Eric, he is a tech, he knows his ****. He can tell you if there is a way to get factory dual stuff onto yours. That is if you want factory stuff.


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