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1989 Mazda RX7 Convertible battery keeps draining

We are the original owners on this car. It has only 28,000 miles on it. Over the last 5 years or more we noticed that something is draining the battery. We have gone to several different Mazda dealerships over the years and they say they cannot locate the problem. After constantly replacing batteries we now just undo the battery cables when it is parked. I would like to be able to use and trust this car but it is a big pain to constantly have to lift the hood and disconnect the battery cables every time we are parked for any length of time. Has anyone had this problem?

A lot of people have this problem. You need to find a good independent mechanic who will “isolate” the problem. It’s a simple task but is time consuming. Each fuse or relay has to be removed and the current draw checked. When the current draw is removed then you know where to start looking. That’s the key to resolving the problem. Taking the vehicle in to a dealership is a never ending circle that’s usually very expensive. A good mechanic will know where the normal current draw is and will not chase a needle in a haystack.

I would remove one fuse at a time, for a day each, when the car is not in use, and see if the drain occurs or not. It might take a week or so but you will likely isolate the shorting circuit yourself. Then you can decide if you can leave the fuse out or enlist the help of a professional to correct the problem.

You don’t have to remove both cables,just remove the negative (-) one or have your mechanic hook up a quick-disconnect coupler on it. Then you only have to turn a knob to connect or disconnect.