Alternator Replacement ·
Diesel Alternator ·
F-250 ·
F-350 ·
Ford Super Duty ·
High Output Alternator ·
Power Stroke ·
Truck Alternator ·
Ford F-250/F-350 Super Duty Alternator: Replacement Guide, Costs & Upgrade Options
The Ford F-250 and F-350 Super Duty are the workhorses of the truck world — and among the most electrically demanding platforms in the JS Alternators lineup. Between heavy towing accessories, upfitting, off-road builds, and serious car audio, the Super Duty needs more alternator than the stock unit provides.
Super Duty Alternator Specs by Year and Engine
| Years | Engine | Stock Output | JS Alternators |
|---|---|---|---|
| 2003–2007 F-250/350 | 5.4L V8 | 110–130A | 250–370A |
| 2003–2007 F-250/350 | 6.8L V10 | 130–145A | 250–370A |
| 2008–2010 F-250/350 | 5.4L V8 | 135A | 250–370A |
| 2011–2016 F-250/350 | 6.2L V8 | 150–180A | 250–370A |
| 2017–2022 F-250/350 | 6.2L V8 | 180A | 250–370A |
| 2017–present F-250/350 | 7.3L V8 Godzilla | 180–220A | 250–320A |
Note: Diesel Super Duty (6.0L, 6.4L, 6.7L Power Stroke) alternator options vary — contact JS Alternators directly for diesel applications.
Ford Smart Charge on Super Duty
All 2006+ Super Duty trucks use Ford's Smart Charge system. At highway cruise, voltage may read 12.5–13.2V — normal. JS Alternators Super Duty units retain full Smart Charge compatibility.
Super Duty Alternator Replacement Cost
| Option | Parts | Shop Total |
|---|---|---|
| OEM Ford | $220–$400 | $350–$600 |
| Remanufactured | $140–$250 | $270–$450 |
| JS Alternators 250A+ | $300–$450 | $430–$650 |