I have a rather unique charging issue here. Trying to avoid the dealership at all costs lol. So this 2009 Tribute Charges fine for 60 seconds. Alternator puts out 14.8 volts steady. After one minute the rpm drop by about 500 and the voltage drops to 8.4 volts. If you turn the engine off then crank it back up it does the same thing again, after exactly one minute. I've replaced the alternator three times and the battery once. I've checked every ground connection and every fuse. I've traced the battery cables in hopes of finding a fusible link with no luck. I really hoping it's not the pcm. It's a 2009 Tribute S with a 3.0. Any help would be greatly appreciated.

 

What is your battery voltage, engine off?

8.4V either indicates a massive drain (like more than starting current) or a failed battery with the alt offline. Even if you have already replaced it, I'd start with the check above.

Assume its <not> a hybrid?