Dash Low Battery Issue

[DKRITTER]

I have a 2013 Newmar Dutch Star 4318, the dash low battery warning comes on constantly.

We had been on 2 trips in July w/o issue. We were taking it in to NIRVC for it's annual maintenances and we almost immediately started having issues. It was July in Texas so I had the dash air and generator on with the roof A/C's running. It started shortly after leaving the house and ramped up as I drove to the Newmar dealer.
I asked them to take a look along with the maintenance being done. Their capacity was to load test the batteries which were 60% and 80% so both passed. They referred me to a Freightliner dealer.
I drove it home all the while the charge indicator being below 13V. Tested the batteries they were just over 12v. Plugged it in over night and they were 12.7 the next day.
I tried getting hold of Premier Truck Group in Fort Worth for almost a week and never actually spoke to anyone. A machine answers the phone and says press 1 for..., I left several messages nothing. I got online, nothing.

I took it to an independent diesel shop yesterday, they load tested the batteries and alternator and said all passed. They were charging all last night and will let me know today.

It has a 450hp Cummins ISL engine.

Anyone with experience one this?

 

[Kevin D Pem]

If turning the A/C off and light stays on the alternator brushes may be the issue.

If the brushes have dust in the holders it can be intermittent.

 

[DKRITTER]

Long story short;
I went to a diesel shop and the alternator was the issue. I had it replaced as well as new chassis batteries. All appears to be good.