Battery Drain - Current Leak - 93 Mazda MX6

I have a .4 amp current leak on my battery with everything turned off on the car. I have pulled all the fuses, one at a time, and en mass but the leak persists. I have replaced the battery but I don’t leave it connected. I don’t drive the car much.

Do the same thing. Only this time start pulling relays.


If you didn’t isolate the alternator then remove the connector on the back side of it and see if that helps. Normal current draw should be around 30ma. or less as a guess, so that is over 10 times the normal draw.

Thanks, I tried that without success.

  • Paul

You might want to check your ammeter. Use a signal or marker light from your vehicle of a know wattage and calculate the current. It won’t be exact, but it will tell you if your equipment is in the ballpark.

I found out, from reading the manual, that there is a second fuse block on this car that I didn’t know about. It’s under the dash on the driver side fender wall, in the cabin - very well hidden but obvious if you know where to look. I will do further testing. - Paul

I found the second fuse panel and pulled all those fuses; then went to the one under the hood and pulled all those fuses. I still had a .4 amp current drain on the battery. Then I pulled all the relays that I could find under the hood. There were something like 10 or 12 of them. Nothing that I do stops the leak. I still have a current leak with everything shut off. HELP…

Have you checked to see if there has been any extra connection made at, or near the battery that would explain an extra current path? There should be a main fuse under the hood and pulling it out should kill everything. If it doesn’t I would have to think an extra circuit has been added at the battery source. Find out what lead from the positive post of the battery carries the unknown load current and try to follow it.

Are you sure you are reading your meter correctly? This is the time to use the test light test. Put the test light in series with the negative battery post and the cable, if its really pulling .4 amps that light will be burning as bright as it is possible. If its dim (really dim) perhaps you are reading 4 milliamps.

Well, I tried the meter on my other car and it doesn’t show any current draw when everything is off. Just on the Mazda MX6. Also if you disconnect the positive battery lead with everything off and just touch it to the battery post you get a visible spark every time; and it will kill the battery in a few days, so, I think there is a definite current drain. It’s .4 amps. I have a digital Fluke multi meter and I know how to read it. I checked the trunk and glove box at night to see if there was a light on.

Good choice on the meter.

Have you found out which wire coming from the battery is carrying the unknown load current?

Another thought. I know you removed the rear connector to the alternator to isolate any trouble there and found none. Did you try removing the main lead to isolate things that way also? If not, you might try that though that lead should be fused and don’t forget it is hot to the battery so don’t short it out to ground.

No one says .4 amps they say 400milli amps espicially when searching for a draw. Your draw is much higher that any single interior light. I am thinking module.