Thanks for sharing this @Jrod-13. Very similar story here. The original alternator in our 2011 Edge died around 200k. I installed a replacement from AutoZone and after a few weeks, the charging system light was coming on, along with the fluctuating voltage. I assumed I just got a bad alternator. I returned it to AutoZone and they refunded it no problem. Then I tried a more expensive new NAPA unit, and experienced the same problem. However, NAPA will not refund the defective part! Anyway, after reading your post I bought a Motorcraft unit on Rock Auto and my problems are solved. It's been a couple of months and the voltage perfect. Lessons learned: buy Motorcraft alternators and avoid NAPA.