Based on the below, I assume that means I need to replace the alternator ?

[Mbrooks420]

Alternator Rebuild Kit for 2004-2008 Ford Explorer 4.0L with 3G Regulator Brushes Bearings - 8519RK

<h3>Description</h3> <p>Alternator Repair / Rebuild Kit With Voltage Regulator, Bearings, Brushes </p> <ul> <li>Voltage Regulator with Brushes, Terminals: I-S-A Terminals, 14.6 Voltage set point, Replacing Ford VP4L2U-10316-AA Other F794HD </li> <li>Brush Holder Assembly with Brushes, Replacing...

www.maniacelectricmotors.com

Here, maybe.