okay, so the other day i noticed on the little volt meeter gauge that my volts are dipping around 13-14v and my idol is dipping some times also...i turn head lights on and roll windows up and it drops to 12 volts! now is this my alternator or i need a new battery? its a 2003 with 30k miles both of these items are the ones from the factory.

 

could be a combination of both. Start with the battery though, 5 years/30k miles is about when they go out. Signs of a fading battery could be shown during starting the car up.

You can get an altenator test done, they have a machine that hooks to your battery. Actually is fairly painless and if you upgraded your warranty the altenator is covered under warranty also. w00t

 

That sounds pretty normal to me; you're only dropping 2V when turning on the headlights and putting up the windows. Both of those actions can draw a good bit of power and increase the electrical load on the charging system. Either way 5 years is about time when factory batteries start to fail, so it may be worth it to change your battery out now before it leaves you stranded.

 

you can always have a shop to a voltage drop test on your charging/starting system.....i know for a fact that the starting system should have less than .5 volts of voltage draw when you start the car.......if your alternator is charging, but not to its capacity-probably 45-60 amps for most cars- then the bushings are probably worn out.....i have a hard time thinking the field windings are damaged or defective....the buchings are like tiny brake pads almost that press up against the inside of the stator.....if youre alternator is bad, thats probably why

 

Most oem alternator last more than 100,000 miles unles abused with system mods like amps/stereo/lights.

Batteries may only last 3 years depending.

 

Actually i just had to replace my alternator at 65k miles because the bearings were bad. It was acutally OVER charging. Made a HORRID squealing noise and the car sputtered and died. They changed the alternator and now its gravy. for now.