HellloJust picked up a 2000 Newmar Dutch Star that has been sitting for 4-5 years (long story). Both chassis batteries replaced recently and had a pre trip inspection by a mobile mechanic before I picked it up. Starting in FL voltmeter was above 12v and by Atlanta it was bouncing from 8-11v. I had generator on for roof air. Stopped by Love service center and counter guy used a voltmeter and confirmed 11v with engine running and no electrical load. Couldn't repair it there so stopped at Walmart and shut engine off but left generator on. Tried to restart to see how low and it didn't start engine and shut generator off. Used the switch to couple house batteries and started generator and went in and got a 40amp battery charger and 50' thick gauge extension cord. I plugged in charger in garage outlet and set charger on 40 amps. I checked the specs of Interstate chassis batteries (31 MHD) and they are rated at 1190 amps.Does it sound like alternator failure? I plan on charging for 7 hours will that last the 10 hour ride home if I turn off all electrical loads?Any other suggestions?

The battery probably won't last the 7 hour trip home - especially if the headlights come on automatically when the engine is running as many MHs do. You can probably find the fuse to kill the lights, but don't pull the ones for the brakes or turn signals.The battery will take the biggest part of the charge in the first several hours. I'd stop midway and charge it some more. Don't run the dash air. Is there anyway to keep the generator running with the battery charger charging while going down the road? Get some duct tape and tape the extension cord in place to the side of the MH if needed.Bill

It is possible you could have a failed battery isolator. Do you have a Cole-Hersee battery isolator? If so, try a jumper between either battery stud and the alternator stud with the engine running, this will provide field voltage to the alternator. If you get around 13.7 VDC you'll know the isolator is bad.

Sure sounds like an alternator failure to me. That vintage should be a non-electronic version, so being a diesel once started it should run until you shut it off.

I have no tools and limited knowledge of the battery isolated. I found an archived thread here describing a alternator failure on a 8.3l and it seems it's not uncommon with miles.I found the manufacturer and chassis paperwork and in Cummins troubleshooting it said open circuit or blown fuse could be a possibility.When the installed the batteries before I arrived they did something wrong which blew the engine and trans computer fuses so it wouldn't start. The mobile mechanic replaced 2 fuses and it started. I wonder if there's something in the charging circuit?I'm waiting fir daylight and I'll try the first Camping World.

Run your generator and use the new battery charger to charge your engine batteries to get home. You may have a block heater outlet in the engine area to plug the charger into and a switch on the dash to turn that 120V outlet on...unplug the heater if there is a cord plugged into the outlet.You have a fuel shut off solenoid that manually pulls a lever on/off and at a low voltage it may stop holding it on.

Low voltage on 2000 Dutch Star 8.3L | Good Sam Community

Trackrig
Explorer II
May 30, 2017
The battery probably won't last the 7 hour trip home - especially if the headlights come on automatically when the engine is running as many MHs do. You can probably find the fuse to kill the lights, but don't pull the ones for the brakes or turn signals.

The battery will take the biggest part of the charge in the first several hours. I'd stop midway and charge it some more. Don't run the dash air. Is there anyway to keep the generator running with the battery charger charging while going down the road? Get some duct tape and tape the extension cord in place to the side of the MH if needed.

Bill
Jamboree89
Explorer
May 30, 2017
It is possible you could have a failed battery isolator. Do you have a Cole-Hersee battery isolator? If so, try a jumper between either battery stud and the alternator stud with the engine running, this will provide field voltage to the alternator. If you get around 13.7 VDC you'll know the isolator is bad.
Bruce_Brown
Moderator
May 30, 2017
Sure sounds like an alternator failure to me.

That vintage should be a non-electronic version, so being a diesel once started it should run until you shut it off.
rowekmr
Explorer
May 30, 2017
I have no tools and limited knowledge of the battery isolated. I found an archived thread here describing a alternator failure on a 8.3l and it seems it's not uncommon with miles.

I found the manufacturer and chassis paperwork and in Cummins troubleshooting it said open circuit or blown fuse could be a possibility.

When the installed the batteries before I arrived they did something wrong which blew the engine and trans computer fuses so it wouldn't start. The mobile mechanic replaced 2 fuses and it started. I wonder if there's something in the charging circuit?

I'm waiting fir daylight and I'll try the first Camping World.
Ivylog
Explorer III
May 30, 2017
Run your generator and use the new battery charger to charge your engine batteries to get home. You may have a block heater outlet in the engine area to plug the charger into and a switch on the dash to turn that 120V outlet on...unplug the heater if there is a cord plugged into the outlet.

You have a fuel shut off solenoid that manually pulls a lever on/off and at a low voltage it may stop holding it on.
dougrainer
Nomad
May 30, 2017
Your year Newmar, the chassis battery starts the Genset. The Chassis Alternator charging system for the Chassis batteries is ALL Chassis makers. NO additional relay's or wiring by Newmar. IF you show no charge voltage your Alternator is probably bad. I would get to the Chassis maker service center first thing. Do not wait to get home. Doug
rowekmr
Explorer
May 30, 2017
Thanks everyone for suggestions.
Stuck in between a rock and hard place. I charged chassis batteries overnight. Engine started fine with them and showed a voltage of 13.4 engine stopped/no load and 13.1 with engine running. I cleaned all terminals and rechecked voltage. I bought battery jumpers and ran them from the house to chassis battery. Started engine and checked all voltages again then turned on generator and inverter/charger. Will check wiring and voltage every 2 hours. Will see if I can limp home and get everything fixed (found minor stuff) at once at a reputable dealer close to home.
dougrainer
Nomad
May 30, 2017
Take a toothpick and jump the Battery Boost switch to stay ON all the time. Your system, once the chassis voltage drops below 13.1 volts and lower, the Intellitech system kicks out the charge relay that combines both chassis and coach banks. Once that happens, the chassis engine/genset and dash appliances will quickly drain the chassis and the engine and genset will die. By jumping the battery boost, that allows the Inverter/Charger to charge BOTH Chassis and Coach and not have to worry about the chassis draining down or the Intellitec charge system from kicking out from low voltage. Doug
Rickieblue
Explorer
May 30, 2017
rowekmr wrote:

When the installed the batteries before I arrived they did something wrong which blew the engine and trans computer fuses so it wouldn't start. The mobile mechanic replaced 2 fuses and it started. I wonder if there's something in the charging circuit?

BINGO
I would guess when the battery installer hooked the battery cables backwards..that blew the diodes in the alternator.....a new delco alternator should be very easy to obtain and install in your coach
rowekmr
Explorer
May 31, 2017
Just made it home thanks again for all the info and ideas. I learn ALOT about the electrical system in a short amount of time. I'll update when I find out what exactly was wrong hoping this may help someone else in similar situation.