Dead Battery

[silverj]

Your battery is fine, you need to look elsewhere, if your battery was bad when you checked voltage with the lights on the voltage would drop significantly.  I would take a good look at your connections at the battery and your grounds.  Could be something like the starter having a bad spot in it too.

[CoggedBelt75]

I had a problem like this not to long ago. The battery has been draining down on me for a while. Was charging fine while driving but during the night the dash voltage meter would show around 11 volts. Let her sit for 2 days and it was sitting around 10. So Friday I decided to start finding the cause, even tho when it comes to electrical I'm not the brightest bulb shining. Put it on a charger and brought it up to a full charge the night before and disconnected the alternator to eliminate a bad diode creating a drain. Friday morning it was low again so the alternator wasn't to blame. Brought it back up to full charge again. Pulled the power wire from the stereo (aftermarket) since it draws enough power to keep the clock set. I used a test light instead of a meter so I wouldn't have to be standing over the meter to see what was going on. I disconnected the negative battery cable and connected the test light leads between the - post and the cable end. The light lit up which meant I did have an open circuit somewhere. Watching the light, I started pulling fuses. Still lit. Pulled relays to fans and fuel pump. Nothing yet. To simplify things, instead of getting under the seat and pulling the fuses from the stereo amps I just unhooked the power wires from the junction box. The light went out! Hooked one of them back up and no light. Unhooked that one and then the other. The light came back on. Thought maybe the wires running under the carpet might have rubbed thru somewhere so I ran some temporary wires and hooked it back up. The light was back on again. So something inside the amp has a problem that was keeping a constant draw on the battery. So until I find out why the amp is doing this I just left it unplugged. Battery hasn't skipped a beat since.

Hope your problem is something as simple as this.

[hondarider188]

well i cant find a draw on the engine with either a test light or a multimeter. I took the battery into walmart and checker and they both tested it. and said that it was fine. so I just dont know.

[CoggedBelt75]

I have a 1983 Chevy k10 silverado my  battery suddenly went dead after just a couple of days. It has never done it before until now after it has been cold for a few weeks. I cant find anything that is on no light or radio. The battery is new, the last owner put it in a couple of months ago. I traded out the battery for a old one i had and it started the truck right up so i plugged it in to charge overnight, then this morning i unplugged it.When i went back out tonight the battery was once again dead.just barely to push over one small crank and then to just kick on the starter. The battery is still reading a full 12 volts. So any ideas.

Thought I would start from the beginning since I'm a bit confused. You say it is dead but then say it has full volts. So the battery actually has the voltage but just acts like a dead one when trying to start? A fully charged battery will read about 12.6 volts with a volt meter. If it reads 12.4 or less, it is low.

And using the test light, you only disconnected the negative cable from the battery. And then connected one lead of the light to the negative post on the battery and the other lead to the cable end. And the light still didn't flicker or light up?

[bake74]

     Electrical shorts are a pain in the ?.  Sounds like you have a ghost short and the only way to find it is to track it down, one system at a time.
     I know this is not what you wanted to hear, but I had a blazer once that had a ghost short, it took me a couple of months going back and forth to find the actual problem.

[hondarider188]

Thanks coggedbelt i didnt connect the test light from the negative to the cable. What i did was connect the negative post to the frame and I always thought that was how you tested for a draw on battery. Anyway i tried what you suggested and the light did come on. I also hooked up the multimeter and the battery it self read 12.3 volts which i did expect because i've been running and testing the lights all afternoon. When i hooked it up to the negative post and the cable i was getting a reading of 12.1 so pretty much all that my battery is putting out. So does this mean that i do indead have a draw?

[CoggedBelt75]

Yes, if the light came on hooking it up as I described then you do have something drawing power. Leaving it hooked up like stated, begin pulling fuses one at a time until the light goes off. I would disconnect the alternator first to eliminate a bad diode pulling the power. Then the fuses and any relays you may have. Sooner or later you will find the circuit that is causing this. As I found out for myself, it is time consuming and frustrating task (especially when I really don't know much about electrical troubleshooting) for sure but it has to be done. Let us know how you come out on this.

[CoggedBelt75]

Checking in to see if you made any progress.

[hondarider188]

Yeah i have made a little, but been sick so trying to stay rested. I did eliminate the alternator and i did find at least one of my draws which is the radio, because for some weird reason the radio has no power supply in the fuse panel to the last owner made a Y connection into the horn power so then i had no horn. So to get my horn back i plugged the radio into the accesory power supply so im assuming that is one of my draws. for the other one yet i dont know for the test light was pretty bright and now its dull so one more to find.

[CoggedBelt75]

I feel your pain as I've been home 3 days with the flu. Keep in mind that most newer radios will draw a small amount of power for memory or the clock. I yours does, keep it unplugged while testing. Sooner or later the light will stay dark, then all will be good.

[hondarider188]

well I finally found the source of the draw. So yesterday i was feeling pretty good and decided to go out and work on the battery issue so i pulled all the fuses and it still didnt go out. So i tried the fog lights which have a inline fuse, but still no luck. So i decided to try the alternator again just for kix and what do you know the light went out. So now it looks like i need a new alternator. And the only reason i didnt spot it before was because the radio pulling to I wasnt able to notice the alternator going out. So now my next question is that how many amps should i be looking for the new alternator to put out?

[CoggedBelt75]

Glad you found it. I would go ahead and take the alternator to the parts store and have them test it. If it is in fact the diode trio, you could replace it yourself and save a whole bunch of money. Only costs around 5 bucks for the part.

As for what amp if you replace the alternator, unless you have added several things that draw ALOT of amps, just get what originally came in the truck. I believe yours calls for 2 different ones, a 63 and a 78 amp. I would go with the 78.

Let us know how things are after the alternator is either fixed or replaced.

[bake74]

well I finally found the source of the draw. So yesterday i was feeling pretty good and decided to go out and work on the battery issue so i pulled all the fuses and it still didnt go out. So i tried the fog lights which have a inline fuse, but still no luck. So i decided to try the alternator again just for kix and what do you know the light went out. So now it looks like i need a new alternator. And the only reason i didnt spot it before was because the radio pulling to I wasnt able to notice the alternator going out. So now my next question is that how many amps should i be looking for the new alternator to put out?

     It always sucks when there is more than 1 problem, but now you have gained some great experience for the next time, or to help others with.

[hondarider188]

thanks for the help and that makes me glad i can just replace the diode if that is what it turns out to be. Where can i get it tested at? does oreilly auto or autozone do it, or even walmart?

[CoggedBelt75]

Take the alternator to either the zone or o'reilly's and they will put it on their machine and test it for you. Costs nothing to do this. If it is a diode failure, if you feel comfortable breaking the case open, it's a simple matter of just swapping it out. But the windings could also be shorting also. In that case it will be time to replace the whole unit.