2011 F150 XLT, 5.0
Hi everyone, I have a very aggravating problem I've been living with for at least 2 years. In certain circumstances the voltage sags on my truck and the battery alarm comes on. The circumstances are always the same, coming out of a sharp right turn or stopping going down a steep hill. I drive down a long 270 degree down hill off ramp everyday for work, while going down the ramp I will see my headlights start to dim. Then at the end when I straighten out on the highway the battery alarm will come on, this happens almost every time. I bought a voltage meter that goes in to the 12v outlet, normal driving the voltage runs steady at 14.8-14.9. During these events it will drop to 12.8-13.0

What I have done:
-New battery
-New Alternator
-Both have tested good multiple times
-Replaced the positive battery terminal (Followed Youtube video and converted it to a Factor crimp style Lincoln terminal)
-Fuse 27 Relocation Complete (note the battery alarm issue was going on before this work was done)

Any and all advice will be helpful, Thanks!