I have a 10 AE it has a stock alternator and a normal old battery. i turn it on and it idles fine about 1500 . when i turn on the head lights the idle drops and it feels like its going to shut of. Even on the AFR guage when the lights are off its at orange and one green bar once the head lights come on it drops down to red or past red to nothing at all on the guage. could it be the battery or the alternator ? ANY SUGESTIONS ?

If you need to see the other mods on the car just check the signature

 

If you rev the engine do the lights get brighter, if so its probably your battery. Mine did the same thing. Optima Red Top too...