Driving the truck this morning about 5 minutes in my check gauge illuminates, and my volt gauge drops off to zero, pulled over and checked to see if I still had my serp belt, looked good got to work.

Got off work, checked my battery voltage, 11.5 ish with the truck off, started it and showed 11.3 ish, check gauges took 5 min to illuminate again.

Drove it home, voltage was ~11.1 when I got home. Checked the codes and it was showing
P2503-CHARGING SYSTEM OUTPUT LOW

Went and grabbed a new alternator, 13.2v once installed, still low. Check gauges doesn't happen anymore, but it's still a far cry from 14.7V.

Showing codes now:
P0622-GENERATOR FIELD NOT SWITCHING PROPERLY
and still P2503-CHARGING SYSTEM OUTPUT LOW

Suggestions welcome! Thanks guys!

 

Did you charge your batteries prior to installing the new alt?

 

Sounds like you may have a issue with the new alternator. You can get a voltage regulator set for any voltage you want. If you can find a rebuild shop near you get them to put the new alternator on the test bench and see what it is charging at. I don't know if our alternators have brushes or not but in a brush less alternator the voltage regulator controls voltage to a coil in side the alternator case called the field coil. The more voltage fed to that field coil the higher the output of the alternator. On a brushed alternator the voltage regulator sends voltage to the brushes to control the output of the alternator. If you are near east TN quality auto electric is the best in Knoxville.