Super Duty, not OBS

The 7.3L ran in two very different trucks. The 1999 Super Duty body brought a new bracket and charging arrangement, and takes a different alternator from the 1995-1998 OBS truck. If yours is a 1998 or earlier, see the OBS page instead.

The last of the pre-emissions Power Strokes

The 7.3L is widely regarded as the most durable engine Ford put in a Super Duty, which is why so many are still working and why owners invest in them. These trucks routinely have 300,000 miles and a second life as a plow truck, tow rig or service vehicle.

That longevity is exactly why charging becomes a problem. A twenty-five year old alternator is not producing what it did new, and the accessories added over that time — plow, lighting, inverter, winch — were never in the original calculation.

2003 straddles two engines

The 6.0L arrived partway through 2003. A 2003 Super Duty could be either engine. Confirm which you have before ordering.

Dual batteries

Replace both at once and match them. On a truck this age, a tired battery will pull a new one down within months.

Don't skip the wiring

Factory cable on a truck this old is undersized and likely corroded at the terminations. See our Big 3 wiring upgrade guide.

Compare the 1995-1998 OBS and 6.0L, or browse all Power Stroke alternators.