ok i just put new batteries in my truck a month ago, its a 2004 ford f250. last nite i filled my truck up with fuel and on the way home the batt. light came on, so i checked the cables and everything was tight. today i went to start my truck and it seamed like it didnt have enough juice to start then it fired up and everything was good. i kno nothing was left on overnite, today leavin my buddys place the truck wouldnt start and the fuel gauge read low enough for the light to come on, so whats goin on?

 

it was the alt. and they want 600 bucks