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otrfun's avatar
otrfun
Explorer II
Feb 15, 2021

Cold Ambient Temps = Higher Alternator Voltage?

Our '16 Ram 3500 Cummins (220a alternator) typically charges around 14.3 - 14.4v about 95% of the time. On occasion charge voltage will drop to 13.9v on a long trip when the batteries get topped-off ...
Fuller_Johnson's avatar
Fuller_Johnson
Explorer II
Feb 15, 2021
The Dodge Cummins engine has Grid Heaters in the intake for cold weather starting. This will cause the voltage to drop after starting in cold weather. The heater will cycle on and off until the intake manifold reaches 60 degrees or you go over about 7 MPH. I think that's what you are seeing.

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