System voltage low

[Black_betty]

Hello I own a 2015 ram ecodiesel fully deleted with SFT tune. I recently got a low power mode on my dash, truck jerked a stalled. Lights went dim and hazard lights were losing power. Jumped it off got a new battery put in it, ran fine and light came on and said (system voltage low)but the engines rpm’s are fluctuating and almost wants to stall at idle. With a slight tick coming from the passenger side. Any ideas to fix would be greatly appreciated as this truck is not only my baby but my daily driver. Thanks

 

[Tremper126]

Alternator maybe?

 

[Black_betty]

Alternator maybe?

That’s exactly what it was. Apparently the battery that was put in the truck a year ago was way too small for it and drained the alternator. The bearings went out inside and that was the metal sound under the hood. Thanks for the reply!