You indicated the alternator output was 14.71. How was that checked on the vehicle or bench tested?
If it is dropping to 11.26 at the battery when running, the alternator isn't doing anything.
Let me know how it was tested. If on the vehicle, we need to confirm it is getting power from the battery. If it was bench tested, then I will know the regulator isn't the issue.
If it was bench-tested, I need you to check for 12v at the B terminal and the IG terminal on the alternator. Do this with the key on.
If there is no power to either, check fuse 1 in the under-hood fuse box and fuse 3 in the fuse panel in the vehicle. If the fuses both check good, it is important to confirm they have power. Here is a link you may find helpful:
I attached the charging system wiring schematic below for your review. I had to cut the pic in half to make it readable but did overlap the two so you can follow from one to the next.
Let me know what you find or if you have questions
Images (Click to enlarge)
Monday, March 28th, 2022 AT 6:45 PM