Learn how to diagnose and fix parasitic battery drain in modern vehicles. From glove box lights and aftermarket alarms to failing modules and wiring faults, this in-depth guide walks you step-by-step through testing, common causes, and safe DIY repairs before your battery keeps dying.

If your car won’t start after a rainstorm or a thorough wash, water intrusion and moisture-sensitive electrical problems are usually to blame. Learn the most common causes, how to diagnose them at home, and which fixes are DIY-safe versus when you need a mechanic.

If your car battery keeps dying overnight, you may be dealing with a parasitic battery drain. Learn the common electrical causes, how to diagnose the drain at home with a multimeter, and the best repair options before you get stranded again.