My car radio would randomly turn itself on and thus drain the battery. After pulling the radio fuse I disabled the radio, but the car battery still died. Then, I jump-started the battery and at first the car worked fine, but then the battery slowly died again. Can a bad cell in a battery cause the strange electrical system problem with my radio?
Great question. A battery cell problem can't cause the radio to develop a problem, but a radio issue can certainly kill the battery. It sounds like your Sonic has something called parasitic battery drain. The radio may have been part of the problem, but I think there is more. An experienced technician, like one from YourMechanic, can test for, verify, and isolate the parasitic battery drain. An ammeter is used to measure how much current flow is being drawn out of your battery when everything is supposed to be shut off. If it's too high, (over 50 mA), then some specific steps are followed to trace down the source of the drain. A healthy, known good battery will need to be in the car. If you want to have this looked at, a certified professional from YourMechanic can come to your car's location to diagnose the vehicle's electrical system and make any needed repairs.
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