P1149 Alternator 2 High Input
What does P1149 mean on a Ford?
P1149 — Alternator 2 High Input. This Ford-enhanced code applies to Super Duty and E-Series with dual alternators.
Common causes of P1149
- Second alternator overcharging
- Failed voltage regulator in the second unit
- Poor battery cable connection forcing overcompensation
- Field circuit shorted high
- Mismatched replacement alternator
How to fix P1149
- Measure charging voltage at each alternator
- Inspect battery cables and grounds
- Check field control for shorts to power
- Verify correct replacement part number
- Replace the overcharging unit