ok question for the experts, i have a s4 that i keep in colorado, the....
 

car has been sitting for about three months. my friend just went up to bring it to denver. the battery was dead so they had to jump it (i know i forgot to discon the battery) now there is some weird electrical things going on. he says when the brakes are applied the headlights dim, when you roll down the windows the headlights dim, basically some kind of power drain issue. right before i let it sit i had the service done, i mean like that day. the car had been untouched for three mo. i don't think that alternater would just break itself, any ideas? thanks ahead, todd

sounds like you need to charge the battery or replace

Same thing happend to me...
 

I also had my S sit for about 3 or so months. Although my battery started up fine, about two days later, I had similiar problems that you listed. Then another two days and the battery was dead, wouldnt hold a charge, nothing... Had to jump it then dash to the dealer. My guess is the same as expstang's, dead battery.

possible dead cell in batt...

Exact same thing happened to me....replaced the battery and everything was fine.
 

Its as though they have trouble recharging with the alternator after needing a jump....or it was just old. Either way, I'm willing to bet the battery is the issue.

Don't drive it like that a lot, when the batt. is dead it will make the
 

alternator work hard to try to charge it. that will kill the alternator. you need to get a new batt. how old is your batt. does it have any warranty?

When you use too much electrical device there is not as much power for them because the batt is taking the power from the alternator.