ok so i have an 02 ES, have a system in it, and ive noticed recently the headlights have been dimming more often. But a couple of times in the past couple months my cd deck and every thing else would stay on but my digital EQ would shut off then come back on, it only happend twice in like 2 months. Well tonight on my way home every thing went out, deck, EQ, headlights etc. then came back on a second later, then did it again....then when i pulled in to park right as i was reaching for the key to turn off my car it did it again. Is my battery shot, do i have an alternator problem or what? Please help.....

 

Optima battery, heavy-duty alternator. Do you still have the stock battery?

 

its not the stock battery, its like the best out of three choices at autozone but not an optima.....and as for the alternator, from what ive read it doesnt matter what you do to the alternator, your ECU wont accept it....

 

Specture is right, any changes (upgrades) to your alternator will do nothing to boost your output, Your ECU is set to run on preset paramaters and does not adapt to changes, it will charge your battery and power your car the way it was designed to at specific volt/ amp levels.

i have the same problem with dimming on my car i bought it in 4 times cause i noticed that my RPM needle was dancing a little to much (they said it is do to the charging (topping up the battery) if any juice is zapped from it. even a slight drain may be to much for your alternator.

when they did the test, and i was playing my Sony Deck and AMP/ 1 SUB at low volume.
they could see the slight drain on my battery,

say if 14.00 is the base voltage, and then the music and headlights and signal lights the drain would pull it down to 13.80, then the alternator would kick in causing the dimming effect and pull the voltage back up to 14.00,

One thing i noticed is that when the Rad Fan kicks in, it gives a heavy kick to your Volt level, that usually happens when your car is parked, or you come to a stop for a fews seconds.

Getting back to the turning off thing, i had the same problem when i was still running on my old OEM Panasonic battery, the voltage would go down to 11 or 10 volts when i was playing my music because the battery was failing.

my only observation is that the Alternator charnging strength is relativly weak , so if your battery is shot then eventually your core voltage will continue to drop as you put more load on it, turning , braking, headlight, music, and what ever else your care is doing.

thats my two cents

 

Do you have a capacitor for your system? What kind of system do you have?

 

no capacitor, pioneer deck, pionner digital EQ, some pioneer 6x8 and 6x9 speakers, sony 800 watt amp, profile 600 watt amp 2 12" optimus subs.....

 

You need a capacitor for sure and possibly a stronger battery. You should look into getting at least a half farard if not a 1 farad capacitor with that many amps and two 12"s. That will solve most of your problems