My truck started murdering batteries if I leave it parked for a few days. The first time it happened, I got a brand new battery. Left the truck for a few weeks, and it was dead again. Got it jump started, had a shop check the battery, and they said it was bad again. I replaced the battery AGAIN, and by the next morning, it was dead. My alternator is putting out around 14V. There are no dome lights or rear lights on. I don't have any power features - no power windows, locks, or alarm, or any of that. I just have cruise control, and a radio that's been working fine for two years. No fan noises when I cut it off. The problem only started recently. What could be causing my batteries to die so quickly and frequently?
Hello. If your batteries are dying that fast, then something is staying on electrically in your vehicle. If you do not have power windows or door then this should make it simple to diagnose.
I typically start by checking to see if any circuits are staying on or if any relays are staying engaged. If I find nothing from there, then the issue is typically caused by a bad ignition switch that is not turning off, or a bad body control module. Both of these are very common.
I always start by testing the ignition switch as it is much easier to test and replace than the body control module, which would need to be programmed to the vehicle should it need to be replaced. If you are needing to have the vehicle repaired, consider YourMechanic, as a certified mechanic can come to your home or office to diagnose your battery issue and perform any needed repairs.
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