2014 Battery Low Voltage Light - Still Charging?

[Tonybain42]

I've got a 2014 RAM 2500 Cummins; I've been getting an intermittent low battery voltage light on the dash.

I have a RaceME Ultra and started watching Voltage on it.

The RaceME supply voltage (from the OBD 2 port) stays about 13.8; the pcm voltage also stays around that.

The dash says 13v on the screen when selected.

It jumps a lot when I select the actual alternator voltage on the raceme.

Is this the alternator possibly going out, or just a bad connection somewhere?

Given that the pcm and battery voltage never drops, I think of a bad wire or connection.

I've Googled for similar issues and only found issues where the alternator isn't charging, but mine is.

Sometimes the light stays on for just a minute; other times it's several minutes.

Any help is appreciated.

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[AK Bob]

I've got a 2014 RAM 2500 Cummins; I've been getting an intermittent low battery voltage light on the dash.

I have a RaceME Ultra and started watching Voltage on it.

The RaceME supply voltage (from the OBD 2 port) stays about 13.8; the pcm voltage also stays around that.

The dash says 13v on the screen when selected.

It jumps a lot when I select the actual alternator voltage on the raceme.

Is this the alternator possibly going out, or just a bad connection somewhere?

Given that the pcm and battery voltage never drops, I think of a bad wire or connection.

I've Googled for similar issues and only found issues where the alternator isn't charging, but mine is.

Sometimes the light stays on for just a minute; other times it's several minutes.

Any help is appreciated.

See the attached charging system operation information and scan for any trouble codes.

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[AK Bob]

@Tonybain42 Also check for loose connections starting with the B+ wire that connects the alternator output to the passenger side battery.

See the wiring diagram attached.

Please keep us posted.

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[Tonybain42]

Thanks again, AK Bob!

It seems to come and go.

The alternator voltage displayed on my RaceME Ultra has been OK since I posted last.

In the past three days, it has started happening again.

The alternator voltage jumps significantly, and the battery voltage stays above 13V.

After studying the diagrams you sent, I can only think that the alternator sense wire from the alternator has a bad connection.

It did it pretty constantly for a few hours when I was pulling a trailer and had more load on it than daily driving.

Maybe the engine was vibrating more from the increased load.

If I determine anything, I'll update again.

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