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
Asked by for the 2003 Saab 9-3
You have a bad battery. Have it tested.
1 more answer
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.