odd voltage readings, batt light and P2704?

[wheels04sxt]

ok so a few weeks ago i left for work one moring and all of my gauges both in the dash and in my pillar pods went crazy, lights flickered on and off, car sputtered and spat for a while so i shut it off, let it sit for a min then started up again and it ran fine. however my volt gauge was only reading about 12.8v volts when before it had been around 13.5v to 13.8v

i got the alternator checked and it checked out ok but was a lil under voltage. i decided to go ahead and get a new battery just cause the one in the car was about 3 years old and i wouldnt expect it to last another full summer here in az.

everything has been fine for the past couple weeks after changing the battery and all until last night. i was about 50 yards from pulling in the driveway after driving the car for about 250 miles yesterday when all of a sudden i see my volts drop from 13.8v to 12.0v and my battery light came on in the dash. im not sure what all this means. i do have an mpx udp so i wouldnt expect to get a full 14.5v but waht would causse them to drop so low and the batt light to come on? also im throwin the P2503 and P2704 codes... i did a search and nothing came up for P2704 anyone know what it means?

i was thinkin of going to et a new alt today but figured id post up here for some suggestions before i do so. any help or opinions is greatly apprecited

thanks

nick

[gtxtreme19]

You sure its not p2407? That code may not have squat to do with the battery.
Voltage problems are usually pretty easy to diagnose.
1 check your terminals for corrosion and build up of acid.
2 make sure your connections are tight
3 check all your cables and wires including the grounds running from battery to starter and alternator
4 check your battery and alternator Autozone will do it for free
Even though your battery is new doesn't mean its good.

It shouldn't take you 20 minutes to do those first 3 things
Number 4 you can do pretty easily if you have and know how to use a multimeter. On most older cars you can disconnect the positive battery terminal on the battery and find out pretty quick if its your alt but Idk if that's possible anymore

[wheels04sxt]

yeah i had the alt checked at autozone when i put the new battery in. they said it was slightly under voltage but not to bad...

im pretty nuch a noob when it comes to electrical components and such lol so i figured it was just cause my udp that it was reading a lil low

ill check the batt tomorrow mornin, unhook it with the car runnin, and see waht it looks like. the car still runs and drives. i took it down the street to get a pack of smokes earlier but its still readin 12v on my gauge. battery light didnt come on this time though.

nick