Twice in 2 months my 2012 Toyota 4runner has had a dead battery and the alarm in barely chirping.
The car was turned off, locked, the doors were all locked and no interior lights were on. The battery readily accepted charge and ran fine. Dealer found nothing wrong. What caused this and what do I do about it.
put a voltmeter on the battery while the engine is running. if the voltage is under 12.75 the alternator isn't charging if it is charging then the voltage will be over 13-14
Battery might have a bad cell, have it load tested if alternator is working and also check your battery terminals & terminal wires for corrosion and if tight or not. Engine to frame may be loose or frayed.
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