2012 6.7 Cummins not charging

[Rrp14]

Hey so I’m working on a 2012 ram with a 6.7 Cummins. The alternator isn’t putting any power out so I was trying to test and see if it’s dead or if it’s just not getting the signal from the pcm. What I did was disconnect the small 2 wire plug from the alternator with the engine running and connect one end of my voltmeter to the red wire in it and the other end to the battery(-) I didn’t get any voltage, I did the same with the brown wire except I connected the voltmeter to battery(+) no voltage there ether. So I think ether the pcm or the wires from it are the problem does that seem right? If not does anyone know of a better test?
I wanted to do a full field test but wasn’t exactly sure how? if anyone knows how to do that that would be great
Here’s the wiring diagram

 

[JW2 Innovations]

Others might know how with way you are trying. I usually just pull the alternator and take it to local parts store so they can test it.

 

[Jkbsmns]

Hey did you ever find the issue if it was the pcm? My battery light came on was not charging and than I replaced the alternator and it was charging and fine for about 5 hours of driving than than battery light came on again turned the truck off and back on and started charging again? Trying to test pcm next