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Call or Text (352) 722-5295Alternators on the 2007.5-2009 Ram 6.7L Cummins
The 6.7L Cummins uses a single alternator driven off the serpentine belt. It charges two 12-volt batteries wired in parallel and feeds everything else, including the TIPM that runs the body electrical. The maintenance schedule calls for the serpentine belt at 100,000 miles, so an alternator job on a high-mileage truck is a good time to look at the belt. The biggest draw the alternator has to make up for is the intake grid heater, which keeps cycling after a cold start.
What fails and why
The problems that are documented on these trucks sit around the alternator rather than in it, so test before you replace. Corroded grid heater studs and cables cause voltage dips and slow cranking. Owners report battery cable trouble that shows up as low voltage and intermittent gauges. On 2008 trucks the TIPM can drop power to electrical components at random. Any of those can make a good alternator look bad.
Stock replacement vs. upgrade
Every alternator in this collection is sold as a high-output unit. That makes sense if you have added lights, a winch or other accessories, or if you want more charging headroom for cold starts. We do not publish a factory amperage for these trucks, so read the tag on your old unit or check by VIN before you compare ratings. If you are replacing the batteries at the same time, do both as a matched pair; a mismatched pair shortens the life of the newer battery.
What we carry
Mean Green offers the 1391 high-output alternator and the MG1391SHD, rated at 375 amps, both listed for 2007.5-2023 6.7L Cummins trucks. XDP offers the XD354 HD high-output alternator in a wrinkle black finish, listed for 2007.5-2024 6.7L trucks. If your charge cable is cracked or corroded, replace it along with the alternator so the new unit is not working through a bad connection.
Fitment notes
These alternators are listed across several 6.7L model years, but this page is for the 2007.5-2009 Ram 2500 and 3500. Early 2007 trucks have the 5.9L and are not covered here. Bracket, plug and pulley fitment should match your truck's original unit, so verify by VIN or use the fitment checker on the product page before ordering. Check fitment carefully for 4500/5500 chassis cabs, where most pickup parts do not interchange.
Frequently asked questions
What amperage is the factory alternator on a 2007.5-2009 6.7L?
We do not publish a factory rating, because it could not be confirmed by year alone. Check the tag on the alternator you are replacing, or have us verify by VIN. That gives you a real number to compare against the high-output units here.
Do I need a high-output alternator?
Not on every truck. If yours is stock and the old alternator simply quit, a correct-fitting unit is all you need. A high-output alternator earns its place when you have added electrical load or you start the truck cold often, since the grid heater draws hard on the system after every cold start.
Should I test the batteries before replacing the alternator?
Yes. Slow cranking and low voltage on these trucks often trace back to the batteries, battery cables or grid heater connections. If the batteries are bad, replace both as a matched pair, then check charging output again before you buy an alternator.
Not sure what fits? Call the shop at the number in the header, or use the fitment checker on any product page. We install everything we sell.