2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

Battery drain/short

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Old Apr 11, 2006 | 08:45 PM
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RotorRoy's Avatar
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Battery drain/short

I believe I have a short somewhere in my 86 rx7. I bought a new battery for it but the thing just keeps going dead. I charge the battery but when I wait a couple days to start it, it's always dead. My clock on the dash has also stopped working. I don't know if this has anything to do with it. I have never worked on rx7's before and need help pin pointing the short or whatevers going on. If you could help or give me some pointers about where to start first, it would be appreciated. Thanks
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Old Apr 11, 2006 | 10:36 PM
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i am currently experiencing the exact same problem. i just got a subscription to an online repair manual, and will be looking for a way to troubleshoot it. i am almost positive that it is a short. my clock however keeps flickering in and out, somtimes it is on, and somtimes it isnt. let me know if you find a solution, and i will do the same.
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Old Apr 11, 2006 | 10:45 PM
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The clocks usually go bad like that. I have a bad clock also, it has to do with the solder joints. They are bad, altho this shouldnt effect your battery. If your battery keeps goin dead, maybe you left something on, check the lights and if your hatch is closed all the way. Mine would go dead if i didnt run my car and just let it sit. The alternator charges the battery, so start your car and let it run for awhile. Just do a basic check to make sure that the positive isnt touching the frame or anything. Usually if it's a particular thing getting shorted, the fuse will blow. Carefully glance over your wiring and check your fuses. You also should make sure you have the post securely tightened, loose connections can sometimes cause the battery to slowly drain or act up.
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Old Apr 11, 2006 | 11:39 PM
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i have checked alot of things, i had my battery and alternator checked, my alternator is charging 14 volts, so that is fine, and my battery is good too, and the wiring in between, i have been careful to make sure everything is shut off, and if my hatch is open the security light blinks, so it cant be that, and i dont let the car sit, i've actualy only had it a week, and i've driven it at least 10 times. but i only get about 2 days before i have to charge my battery, so somthing is draining it, and i agree that it should blow a fuse if it is shorting out. i am going to keep checking wiring and trying to find the source of the problem.
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Old Apr 12, 2006 | 09:52 AM
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Connect an ammeter in series with the + terminal of the battery and measure the current draw with the key off. Now pull each fuse and note when the draw disappears. That circuit will be the problem.

It's also common for the regulator or a diode in the alternator to fail, resulting in a draw.
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Old Apr 12, 2006 | 02:23 PM
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I recently had a similar problem. My problem was the connector of the passenger door.


Ref reply above - Another method that may work is:

Disconnect the cable from the negative terminal of the battery and connect a light bulb between the negative terminal of the battery and the battery cable.

When you remove fuses one by one, the light will disappear (or will become much weaker) when you have located the right circuit...



Oivind
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Old Apr 12, 2006 | 02:26 PM
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From: indiana
my problem was a corroded terminal on the batter. when i cleaned the terminal i had no more problems
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Old Apr 12, 2006 | 09:40 PM
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From: mass
thanks for the ideas on how to test it, i was clueless, i was just looking around to see if i could find a wire that looked suspicious, i dont know what i was thinking. haha. now i just have to locate that and add the grounds to fix the 3800 rpm bogging issue.
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Old May 13, 2006 | 06:51 PM
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Originally Posted by Aaron Cake
It's also common for the regulator or a diode in the alternator to fail, resulting in a draw.
Is there a way to test for that sort of problem?
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Old May 14, 2006 | 10:39 AM
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Regulator testing is in the Factory Service Manual. You can also bring the alternator to a local auto parts store.
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