110717 | Genuine GM® Generator Alternator LaCrosse, Regal, Impala, Malibu

1. Charge the Battery

• Replaces the power the battery used to start the engine

• Keeps the battery full so the vehicle can start again

2. Power All Electrical Components

The alternator supplies electricity to:

• Headlights & taillights

• Dashboard & gauges

• Radio & infotainment

• Fuel pump

• Ignition system

• Cooling fans

• Sensors & computers (ECU/PCM)

• A/C system components

Without the alternator, the battery would drain quickly.

3. Maintain Stable Voltage

• Keeps the electrical system at a steady 13.5–14.5 volts

• Prevents surges or drops that can damage electronics

4. Ensure the Vehicle Runs Properly

Modern engines rely heavily on electrical power.
Without a functioning alternator:

• Engine performance drops

• Vehicle can stall

• Electronics malfunction

1. Battery Warning Light On

The battery, ALT, or GEN light on the dashboard comes on or flickers.
This is often the first sign of alternator failure.

2. Dim or Flickering Lights

• Headlights dim at idle and brighten when revved

• Interior lights flicker or weaken

This happens because the alternator isn’t supplying steady power.

3. Electrical Problems

Electronics may act strange or shut off:

• Radio cuts out

• A/C fan slows down

• Power windows move slowly

• Dashboard gauges act erratic

4. Dead or Weak Battery

If the battery dies repeatedly, even after replacement, the alternator may not be charging it.

5. Car Stalls or Has Trouble Running

Modern engines need electricity to run. A failing alternator can cause:

• Stalling

• Rough idle

• Hesitation

• Loss of power steering (in some vehicles)

6. Strange Noises

Failing alternators can make:

• Grinding

• Whining

• Squealing (belt slipping)

7. Burning Smell

A bad alternator can overheat or create friction, causing a smell like:

• Burnt rubber

• Hot wires

8. Low Voltage Reading

With the engine running, battery voltage should be 13.5–14.5 volts.
Lower or fluctuating readings indicate alternator problems.