If I sit in the car and listen to the radio even for 5 minutes or have the keys in the ignition and door open when loading the car, the battery drains completely and I need to get a jump start. All other times the car starts with no problem. Also, there's a constant humming like something not turning off coming from the cigarette lighter and it's never used. Thanks!
Why won't my battery turn over when using accessory power? on 2003 Saab 9-3
by WineSaab in Yountville, CA on January 12, 2012
ANSWER by PARTS GUY , January 12, 2012
You have a bad battery. Have it tested.
ANSWER by Hal... , January 13, 2012
Your battery is too old. Test the voltage while you're cranking it and you'll find it less than 10.5 volts which isn't enough juice to start the car.