Emissions equipment adds load

The 6.7L was the first Cummins to carry a full emissions package — DPF, regeneration, and from 2013 SCR and DEF. Regeneration cycles and DEF heating both draw current that earlier Cummins trucks never had to supply.

That load is continuous and automatic. It is not something you can schedule around, and it sits on top of the grid heater on every cold start.

The 2013 refresh

RAM updated these trucks in 2013 with a different interior, electrical architecture and in some cases a different alternator. Check your model year against the individual product listing rather than assuming the whole 2008-2018 run is interchangeable.

2007 straddles two engines

The 6.7L arrived partway through 2007 alongside the 5.9L common rail. A 2007 truck could be either. See the 5.9L common rail page if yours is the earlier engine.

Dual batteries

Replace both at once and match them. AGM handles the deep cycling of auxiliary loads and diesel vibration far better than a standard flooded battery.

Don't skip the wiring

See our Big 3 wiring upgrade guide.

Compare the 2019 onward trucks, or browse all Cummins alternators.