running voltage reading needed

2001 XJ I need the voltage with the jeep running on circut K20-18-DG, basically the green wire that comes off of the alternator to the PCM I have 12.17 VDC on the G/OR wire trying to figure out if the GR wire gets its voltage from the alternator or the PCM, basically is 0 normal when running.

Sounds right as one wire is ground and the other wire is the wire that the PCM controls the voltage to which in turn controls the output of the alternator.

I dont know what is up then if the PCM is sending out the right voltage.

what kind of problem are you having?

The more specific you can be, the quicker you should get to the source of the problem.

battery is not charging i have checked everything in the charging system every wire is good all battery terminals have been replaced including the cables, and the battery and alternator its self. On the or/gn I have 12 VDC and on the solid green cable I have like .03 VCD, and I beleave that it should be 12 since the alternator itself is already grounded to1 the block, I have also replaced, cleaned all grounds. ihope this helps you help me.