It may be the battery, if the car is running the alternator should still be good. The battery may not be holding charge and supplying your car with reserve power. I would take you car to the autoparts store and have them test the electrical system. They will do this for free and tell you if the alternator and or battery is bad.
Your voltage regulator is shot. It is integrated in your alternator. You need to replace the alternator.
The voltage regulator on a 1989 Chevy Camaro is inside of the alternator. If you are having issues, such as flickering lights, you might have to replace the entire alternator.
The brake lights come on. The alternator should maintain voltage (14.2) unless the alternator is failing or the battery is nearing end of life.
It means that the voltage is going up as the alternator spins faster. 4 posibilities; 1 Your battery is dying and the alternator is working harder to charge it when you accelerate. The lights are comming up to full brightness. 2 You have a bad connection at the battery terminals or frame ground and the battery can't hold the voltage down. The lights are receiving too much voltage and are more likely to fail. 3 The voltage regulator on the alternator is failing and overcharging the battery. The lights are receiving too much voltage and are more likely to fail. 4 The battery needs water. The lights are receiving too much voltage and are more likely to fail.
Because the voltage drops. Depending on what is the problem changing the battery or alternator will help.
The alternator may have a faulty rectifier or faulty voltage regulator
Voltage too high - bad voltage regulator on alternator. I bet your dash lights are very bright also.... Change out that alternator before you start popping other bulbs....
Check the alternator output, you may have a failed voltage regulator or bad brushes in the alternator resulting in an oscillating voltage value. This assumes that the flicker is relalted to engine rpms.
Start car. Turn on all lights, blower etc., that you can. Read voltage across battery terminals. If voltage is 13.5 or more then your alternator is okay. This assumes you have clean connections, good cables.
Sounds like it could be low voltage Battery charged? Alternator working?
In all probability you have a bad battery or a loose connection. If the voltage drops with the motor running, you probably have a bad alternator (or generator) or regulator.
It depends on the load and the voltage. In an automobile, a battery will typically have a voltage of about 12 Volts. If the engine is not running and you turn on the lights, the lights will start drawing current from the battery and the voltage will drop by a volt or so, depending on how strong a charge the battery has. An alternator will produce in the neighborhood of 15 Volts. If it is trying to push current into a system with a fully charged battery, it will only be able to push a few amps. If the voltage in the battery drops, the alternator will be able to push more amps. A completely dead battery will draw the most current (amps).