How to use a multimeter to troubleshoot a car battery drain

If your car battery dies after sitting for two or three days, don't just replace the battery. If there is still a parasitic draw, a new battery will be drained just the same. I once had a car in my shop where the customer had already replaced the battery and the alternator, but it turned out the trunk light switch wasn't cutting off; the light stayed dimly lit even after the car was locked…