need some help please. started up my 94 ranger (automatic) idled up fine. must have idled for about 5 mins had to clean the snow off the windshield and it is cold out. put it in reverse and started backing out and it died. battery light came on. tried it again and the engine turns but won't catch and the battery light stays on. battery is only about 3 months old. never had this problem before ( a fair share of others tho) and the truck was running fine all day. so my question is dead battery get a boost or is there maybe something more going on. sorry new to cars learning as i go. thanx