Check the voltage levels. If the regulator is having a little trouble, the voltage may jump around a little. It's usually not much of a problem, but if you're very concerned, take the vehicle to an auto parts retail store that has the ability to check your charging system.
my problem on my Chevy Blazer was the keyless entry
http://www.YouTube.com/watch?v=E9qlLrQ6v5E
You may have a pull on your batt, or a surge.
I had this problem and it was a bad alternator.
If the lights flicker when the vehicle is running, the alternator is on it's way out.
Sounds like you need a new battery.
Headlights, since they require more power than the inside lights of a car.
why do my lights flicker and interior lights flicker
Flickering headlights on a 2005 Silverado may be caused by faulty relays or electrical wiring. The fuses and lights may also be going out.
It is important to know what is going on inside of a vehicle. The headlights dim when a stereo is turned on or turned up because power is being drawn away from the lights to the stereo.
The primary causes for the lights to flicker inside on a 2002 Chrysler Sebring LXI is a loose bulb or wire. This can occur when the vehicle has experienced rough road conditions and excessive vibration.
LED lights may flicker when burning out because the electrical current becomes unstable as the components inside the LED degrade, causing fluctuations in the light output.
Your lights may flicker because they power is really low. It is very common for them to flicker when there is a storm out.
If the interior lights stay on while driving on a 2002 Impala, there could be a problem with the headlight switch. Check the relay center for the headlights that is just behind the headlight switch.