Posts Tagged: electrical drain car

Battery Drains Overnight But Tests Good

Why Your Car Battery Dies Overnight (Even Though It Tests Good) Quick Summary If your battery drains overnight but tests good on a tester, the battery usually isn’t the problem. What I see most often is a parasitic draw—something in the vehicle staying on and drawing when it shouldn’t. Common culprits include: • Modules that don’t go to sleep • Glove box, dome, or trunk lights that stay on • Aftermarket accessories that continue to draw power • A faulty relay. I never guess on these—I perform a parasitic draw … Read More