* Alternator Failure: This is the most likely culprit. The alternator charges the battery while the engine is running. If it's failing, the battery isn't being charged. This explains the dimming lights (low voltage) and the eventual car death (battery completely drained). The computer systems (like the airbag system and engine control module) rely on a consistent voltage supply; a failing alternator will cause erratic behavior and error codes, leading to the blinking lights.
* Battery Failure: A failing battery can also cause these symptoms. If the battery is old or damaged, it might not hold a charge properly. This would also lead to dimming lights and the car dying. The electrical gremlins from a low voltage supply could trigger the warning lights.
* Loose/Corroded Battery Terminals or Cables: A poor connection at the battery can also prevent proper charging, causing similar symptoms. Check for corrosion or loose connections.
* Wiring Issues: A short circuit or other wiring problem could also be causing the power fluctuations and triggering the warning lights. This is less likely than alternator or battery issues, but possible.
* PCM (Powertrain Control Module) Problem: While less likely to be the *root* cause, a failing PCM could contribute to the erratic behavior and warning lights. A failing PCM is more likely a *symptom* of a larger problem like a failing alternator or short circuit.
What to do:
1. Jump Start (Caution): If the car is completely dead, try jump-starting it. If it starts and runs normally, the problem is likely the alternator or battery. However, *don't* drive it for long distances; the alternator might not be charging properly.
2. Test the Battery and Alternator: Have a mechanic or auto parts store test your battery and alternator. This is the most important step to pinpoint the issue.
3. Check Battery Terminals and Cables: Inspect them for corrosion or looseness. Clean them if necessary.
4. Professional Diagnosis: If you're not comfortable with electrical work, take your Lumina to a qualified mechanic for diagnosis and repair. They can properly diagnose the problem and avoid further damage.
Ignoring this problem is dangerous. Driving with a failing charging system is risky, as you could become stranded, and the erratic electrical behavior could affect critical safety systems.
