Alternators rarely die suddenly — they give 7 distinct warnings first. Catch them early and replacement is cheap; ignore them and you'll be jump-starting on the M4 hard shoulder.
1 — Battery warning light
The classic first symptom. Means charging output has dropped below ~13.5V. Don't ignore — battery is now running the car.
2 — Dim or flickering headlights
Voltage fluctuating as the alternator regulator fails. Often worse at idle.
3 — Whining or growling noise from front of engine
Alternator bearings failing. Listen with the engine cold — easier to hear.
4 — Burning rubber smell
Aux belt slipping on a seized alternator pulley. Replace before the belt breaks.
5 — Electrical glitches
Radio resetting, dash flickering, windows slowing — all signs of voltage dropping under load.
6 — Hard starting (especially cold)
Battery never gets a full charge. Cranking voltage drops below the threshold.
7 — Repeated flat batteries
If a new battery dies in days, alternator output is the cause.
How we fix mobile
Diagnose with a charging-system load test, replace alternator at your driveway in 60–90 minutes on most cars.