A couple of months ago my car started to lose power very quickly throughout the day. At first, I noticed while I was driving (rainy weather) the door open light would flash on and off, along with the overhead lights and eventually stop, leaving the door open light on. After that started happening, I noticed a drain in power when I turned the car off.
Car finally wouldn't start, I took the battery in for a test, but it was only a year old and they said the battery was good, just completely drained. They recharged it for me, I put it back in the car and it starts up just fine. The alternator seems to work fine because voltage levels of the running car are where they should be, and I don't lose any power during or after drives, only between them.
What I've been doing is unplug the battery every time I turn the car off, and when I plug it back in, car starts right up as if a full power. If I start the car multiple times before giving it a rest and unplugging, the power feels weaker.
My car has 166000 miles.
My car has an automatic transmission.
Hi there - yes, you definitely have something draining your battery while the car is parked and shut off. This problem can be diagnosed by connecting an ammeter to the positive (red) battery cable, observe the current drain (likely less than 1 amp), then, one at a time, remove each fuse, check to see if the current drain has dropped to near 0, then reinsert the fuse. This process should identify the faulty circuit in most cases. The specific components on that circuit can then be checked for current drain problems. A professional mechanic, like YourMechanic, can come to your location, and perform this procedure for you, and replace/repair the failing component.
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