Battery dies if positive is not unplugged overnight. How do I fix this?

[dpuma8]

Well, I bought a car from another member here and he failed to mention that I have to unplug the positive cable when I am done with the car for the night otherwise it will run out of juice. So how it is now, I unplug the positive overnight and then put it back on and the car will start fine. Last night I went for a drive and the headlights were very dim.

 

I am very new to fixing old cars. The battery is pretty new so is this an alternator problem or is something sucking the battery juice overnight? If there is something doing this, how do I test to see what is draining my battery?

[BLOZ UP]

If you have a multimeter that can read amps, you can unplug one fuse at a time till the current draw drops. If you don't you can just pull one fuse each night till it stops going dead. Second way is a good way to get a free new battery if it's under warranty.

 

Also, usually you unplug he ground cable when you disconnect the battery. It's "safer."

[dpuma8]

Alright! Thanks a ton. I will try that tonight

[MK1888]

Also, you should be disconnecting the negative, not the positive cable. It's safer that way, since the electrical system is negative-ground.

[blue72]

http://forums.hybridz.org/index.php/topic/85365-battery-keeps-dying/

http://forums.hybridz.org/index.php/topic/37916-battery-drain/

http://grassrootsmotorsports.com/articles/zap/

http://www.wikihow.com/Find-a-Parasitic-Battery-Drain

http://flashoffroad.com/electrical/Batteries/BatteryDrain.html

[Pharaohabq]

If you have a multimeter that can read amps, you can unplug one fuse at a time till the current draw drops. If you don't you can just pull one fuse each night till it stops going dead. Second way is a good way to get a free new battery if it's under warranty.

 

Also, usually you unplug he ground cable when you disconnect the battery. It's "safer."

 

This is almost exactly what I was going to say. Alternatively, you can start pulling fuses with the keys off and out of the ignition, till you get one that's arcing. That'll tell you which circuit has a power leak (short) From there you can troubleshoot what that circuit does and look for the short. A meter is a good idea. In the meantime, Autozone sells a bolt on battery disconnect that you just turn a knob to use.

 

Phar

 

P.S: if your headlights are dim, that could be a clue. Inspect the wires leading to the headlamps running lights and brakes. you may have a short there.

Edited September 22, 2010 by Pharaohabq

[Quetzalcoatl71Z]

Sometimes there are random "parasitic" amperage draws going on. make sure the cables, cable ends, terminals, and battery, etc are all clean and clear of "chia pets" or any other oxidtaions...