The alternator will not set the MIL if it illuminates the charge indicator, you will need to go into the PCM and pull the codes from the module, mine was a P0622

first test battery, then

Pull the small plug from the alternator and repeatedly probe the gray wire with a test light and watch the GEN-F terminal output on a scanner, if the output goes from 0 to over 95% then the PCM and all wiring are good and the issue is the alternator, per the SI

Neal

 

Thanks bronx,
I don't have any aftermarket items installed right now

Neal

 

 

I Finally Had The Time To look for an RVC Fuse and did not have any fuses at all that were labeled as RVC. (Please let me know what RVC stands for as my Fuse Block did not have any Fuse Labeled that way. I took the time to go through every fuse in the Fuse Block under the hood with my Fluke Multimeter and Every One gave me a Zero Reading after zeroing my Test Leads once they were plugged in.
I apologize if my photo size was too large but I wanted to show the difference between the Panel Directory that was originally posted showing the Fuse marked "RVC".
I Wish I had ordered The "Factory Service Manual(s)" Like I did for my 2000 Silverado.
I have tried my code reader several times but I don't get Any Codes even when the Charging System Light and the Service Battery Charging System - came on on the Dash as the Voltmeter had severely dropped until the Vehicle Stalled.
I have never dealt with an issue like this in the past, Replacing the Battery and then my Alternator as well has always Solved the problem, but this time is Very Different !

Fuse Directory of 2008 H2 Underhood Fusebox

 

I just checked RVC (Regulated Voltage Control) ended with the '07 models. '08+ pcm (pin 32) has control.

 

Also, check connector/contacts to the bcs(battery current sensor) or check B+volts KOER when disconnected.

 

Maybe you can take your truck to the local auto parts store and see if they can pull the DTC, then start from there

I'm not sure what level reader they have so will just have to bring it up there and see,

There is a lot of things contained within the charging system that have input to alter the charging range, really need the DTC to know where to start,

Neal

 

Where is the Battery Current Sensor located?

 

Negative cable.

 

For the 08 its just down from the battery on the negative battery cable just below the engine side of the under hood fuse box

Neal