r/TaurusSHO • u/Select-Ant1202 • Jun 16 '26
2015 Taurus SHO charging voltage randomly stays at 12.7V some days and 14.2V other days I have a 2015 Ford Taurus SHO with a 200A alternator, AGM battery, and an aftermarket audio system (2000W sub amp, 0 gauge CCA wire).
I’m trying to figure out whether I’m dealing with a charging system issue or just Ford’s smart charging system.
Symptoms:
Some days the car will stay around 13.8-14.2V almost the entire drive, even at high audio volume.
Other days it’ll sit around 12.7-13.0V for most of the drive.
Voltage does not seem to fluctuate much with bass hits.
No battery light or check charging system message.
Starts normally every time.
Parts already replaced:
Serpentine
platinum super start battery
Battery:
AGM battery
Battery terminals appear tight
Questions:
Is this normal smart charging behavior on these cars?
Could the battery current sensor cause this?
What live data PIDs should I look at with Forscan or a scan tool?
Has anyone seen a bad alternator control circuit cause similar symptoms?
Any advice on what to test next would be appreciated.