Charging issue, strange but true

[Tech By Trade]

First time I have saw this failure. My 5 year old battery was replaced a month or so ago. After filling up with gas at the gas station my check charging system light came on. After work I went home and load tested the battery, it was a little low, but it was reading 12.2v. Threw the charger on it and things got weird. In system with the charger it was still reading 12.2v, it will hit 14.4 out of system. Took my load tester and put it on the wifes escape, just to make sure it wasnt NFG. 14.4v at idle across the battery. Took off the charger and fired up the truck, grabbed a dmm and still at 12.2v. Threw the load tester on the battery and took the dmm to the alternator and low and behold 12.2v. Weird. The battery out of my camper is a 800cca hybrid marine unit, with a fresh charge after last weekend and a power up on the charger. Took a reading, 12.8v before i put it in the truck. Hook it up and it dropped to 12.2v. Fuseable link is reading 0 ohms, 0 ohms across the hot wire as well. My guess is the regulator/diodes on the alternator are shot. Any other time I have had diodes go they either go out our sky rocket cooking the battery although that was on twice on GM's, this is a first time issue on a ford failure for me. The idiot light trip must be set right at 12v, or slightly lower. Too bad a rectifier here costs as much as a reman or I would give that a try. Interesting failure to me to say the least.