Electrical
Alternator
The alternator converts mechanical engine power into electrical power to run the car and recharge the battery.
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Starting & charging flow
Interactive — tap a partTap a part to see how it fits in the system.
What it does
- Converts rotational energy from the belt into AC, rectified to DC
- Charges the battery while running
- Powers everything electrical above battery voltage (around 14 V)
When it fails
- Battery warning light on dash
- Dim or flickering lights
- Battery goes flat after a few days
- Whining noise from the alternator area
How to diagnose
- Measure charging voltage: 13.8–14.6 V at idle is healthy
- Test the battery first — a weak battery hides alternator faults
- Check belt tension and condition
- Load-test with lights and blower on
Maintenance
- Keep the belt correctly tensioned
- Clean the terminals and check the ground strap
- Replace the alternator when brushes or the regulator fail
Use the diagnosis order. When a part fails, confirm each hypothesis with measurements before replacing anything — codes and symptoms overlap.