YES ! ! ! next you know you will be stranded trying to get a jumper it doesnt work until you replace either alternator and battery[both].
voltage increases when when rpms are increased,faulty voltage regulator or alternator
More than likely your alternator is faulty. The alternator is supposed to charge the battery and run the car's electrical system when the engine is running. If your headlights dim it means that not enough electricity is being provided. A simple free test at just about any auto mechanic shop should confirm if the alternator is faulty. If the alternator is faulty, and it is not just due to a loose belt, you want to replace the alternator as soon as possible. Eventually it will fail to charge the battery, and you car won't start.
Headlights,interior lights stop working.checked all fuses. I would suspect the headlight switch and/or the electrical connection at the headlight switch is faulty.
weak or faulty battery, faulty alternator (or slipping alternator belt causing battery not to charge) or faulty starter motor
It can, though it is unlikely -- the alternator and the voltage regulator would both have to be faulty. A faulty alternator will not charge a battery, though, so it may seem normal until the charge put into the battery at the store runs out.
Blown bulbs. Blown fuse. Faulty wiring. Faulty relay. Faulty switch.
Possible causes,- Faulty battery- Alternator belt missing or loose- Faulty Alternator- Alternator harness is open or shorted- Alternator circuit poor electrical connection
The alternator may have a faulty rectifier or faulty voltage regulator
faulty switch
Easiest way is to check the voltage your getting out of it when you have electrical loads on (headlights, radio, blower) If the alternator is faulty the voltage would be low
A faulty alternator, a faulty belt tensioner.
This happened to me with my '98 malibu. It was a faulty circuit board, a common problem in malibu's.