Alternator: lifespan, maintenance and replacement

Typical lifespan: 80,000–150,000 miles.

Maintenance schedule

• Test charging output — Annually
• Inspect belt and connections — Every 6 months

Signs it needs replacing

• Dim or flickering headlights
• Battery keeps dying
• Whining noise from engine
• Warning light on dashboard
• Electrical accessories malfunctioning

Tips

A bad alternator can kill a new battery quickly. Always test both when diagnosing electrical problems.