[john walker's workshop]

you need to put a voltmeter on the battery and see if the charging voltage is in the 13.8-14.2 range. if the battery is not charging, the lights, fuel pump, radio, etc, eventually drain it and the car won't run anymore. the starter may be the problem otherwise. also check the ground from batt to body, and ground from the nose of the trans to body, as well as clean, tight battery connections. post the year of your car for best advice.