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Q: Car experiencing battery drainage

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My car keeps dying during the day. It's usually fine during mid-day, and then by evening it's dead. I've hooked up a test light and pulled each fuse, but the only one we so much as get a flicker for is the IOD Sense1 and 2 fuses. Otherwise the light doesn't even dim. I've also hooked it up and checked each fuse to make sure they were in good condition. I pulled each fuse and checked the output and sit at a steady 12-12.5 volts per the multimeter. I've checked every light source. I had the alternator checked. We don't have a switched out alarm that seems to give some people trouble. There's no other sign of a problem except that we obviously have a drain somewhere, but we can't find it. Considering that I individually pulled each fuse, and it must be an electrical problem, shouldn't it have read with the test light? Any ideas?

A: You may just have a bad battery. I suggest ...

You may just have a bad battery. I suggest you test the battery first before performing any further testing. If it tests OK, you can test for parasitic draw (which is what I think you were attempting to do) by placing a digital multimeter, set to amps, in line with the battery negative cable. Generally, on modern vehicles, the draw should read less than 30 milliamps with all of the loads off.

If it is determined that there is a drain, each fuse should be removed until the reading drops on the meter. When that happens, you’ll know you’ve found the problem circuit. I suggest you have a trained professional, such as one from YourMechanic, diagnose your battery drainage issue and repair this problem.

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