Thread: Battery keeps draining.

Like I said, every alternator can be tested on the car using a simple multimeter. Plain and simple as that if you know what your doing.

Voltage test to start with car running, load test turning on the headlights and see if voltage output drops more than necessary or keeps going down,

AC voltage test, if there is any AC voltage like in this case right here im guaranteeing there is by the problems hes having and symptoms

^agreed. I also got a fuse tester from harbor freight to find whats draining the system. It plugs inwhere the fuse goes, and tells what voltage is coming through, its made for finding power drains, was only 5 bucks and is digital, so it will tell me whats draining my system after i fix the alternator.

like i said it was probably the alternator draining it. lol. If the diodes are bad it has a good solid place for that power to go through the coils and back to ground. Id put money on it. Especially if the problems all started happening at once.

Now if youve had a drain for a long time now then maybe there is an additional problem but in this case from what youve said id say alternator

Hoping thats all just from it, but with how my luck goes lol. Its usually multiple things, cant ever be just one. This weekend we shall find out.

Back from the dead...

So was it the alternator? I'm having a battery drain issue right now. It drains through the negative cable when positive is disconnected ...and also drains thru positive when the negative is disconnected. I recently had an issue w/the headlight/turn signal switch but I have completely pulled switch but still have the issue.

How does the battery drain when it's disconnected? Sounds like just a bad battery not holding a charge or an internal short.

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his positive cable that runs from the bat to the starter was fucked up an rubbed raw on the block/trans..

Not completely disconnected...but yea, hence the dilemma! The battery is brand new...and this is actually the second one cuz the first one suffered the same fate. I installed one of those battery disconnect switches after the first new battery died, thinking that would be a temp fix until I received a new headlight/turn signal switch (which was bad causing the lights to stay on). However, I have since completely removed the switch...as well as an aftermarket alarm I found up under the dash that has never worked and appeared to be disconnected but *did* have a separate ground under the dash. It also looks as if the alternator was replaced not too long ago as it's very clean and new looking...although charges fine when running.

I didn't get a chance to go thru and pull the fuses 1 by 1...will probably start at the fusible links first. Thoughts?

Using a volt meter and with only one side of the battery hooked up (either side, + or -), you can see the voltage dropping like a count down! Of course it drains with both cables connected too. I just thought it was weird that it still drained when the negative was disconnected! Stumped.

Well I'm still confused too. With the negative cable completely disconnected from the battery terminal there is no way for the circuit to be connected. Therefore even if the positive cable is shorting somewhere to ground, with the negative completely disconnected from the negative terminal the current cannot flow. Unless there is an internal short in the battery. I'd still take it back to where you bought it and have them test it separately from the car's wiring system.

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When you are putting the volt meter on it are you probing both the positive and negative terminals of the battery? If the negative cable is completely off the negative terminal and you probe the positive terminal and engine or chassis ground you will see 0 volts (provided you don't have a voltage stabilizer installed). If you probe the positive and negative terminals of the battery, you should see a fairly steady voltage around 12v. If the probe on both terminals with the cable disconnected drops as you described, you have a bad battery.

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