Truck battery problem

[wdgold]

My chevy truck battery after sitting for 2-4 days will not hold a charge, but after I jump the battery it will start fine until the truck sits again for a few days and it turns over fine even if I shut the truck off immediately after I jump it. I had the alternator checked at a reputable shop and it was fine, also checked for any system that may be drawing amps from the battery when the truck is off. I tested the amp draw on the battery when starting, and it was good. My next step would be to change the battery but it is only 2yrs. old, but on the other hand it seems like 80% of electrical problems that I have experienced with vehicles is the battery. Any help would be appreciated.

[Hafnutz]

I bet it's a battery problem. Common problem on side terminal batteries in a GM is the positive post comes loose inside the case and battery starts leaking and you get a poor connection. Sometimes it's just a loose battery cable connection also. Check it out.

[Scott K]

You could bring it in and get a free battery test, charging test done to it, and that would rule them out! Then all you have left is something drawing from the battery.

[ilovefishing]

first thing i would do is if you have access to an ohm meter is take off your negative cable and hook one side of the meter to it and the other to the negative terminal. let sit for at least 5 minnutes plenty of time for the computers to power down. set on the amp setting and start to pull fuses. there should be less than .05amp draw. have the battery load tested because the battery may be 2 years old but could have been on the shelf another 2 years. If you do any off roading with the truck it is possible that one of the cells collapsed causing a christmas tree effect. with one shorted out cell the battery is only as strong as the weakest cell. sorry for putting volts instead of amps (it was a long hot day of work yesterday) good luck to you

I have been an auto mechanic for 3 1/2 years and working on vehichles for over 10

[Jeremy airjer W]

Why would you use a DVOM set to voltage? If your checking for draws you would want to set the multi-meter to amps. Disconnect one terminal of the battery, place one lead of you meter on the battery post and the other end on the now loose cable end. You may have to wait for a couple of minutes for things to power down like ilovefishing mentioned. An exceptable amperage draw would be less than .050 amps or 50 milliamps. If its more than that than its time to start pulling fuses. Remeber that if the hood light is on it will register on the meter as a draw so you may have to unplug it. Opening the doors will also trigger a draw until the dome lights power down.

[wdgold]

Thanks for the help guys.

[wdgold]

I disconnected the neg terminal and waited about 5 min and hooked the DVOM to it and set it to 250 mil amps and it pegged out.

[Scott K]

You need to leave the meter hooked up for this time, the modules will not go to sleep unless they are getting power. Some vehicles take as long as 45 minutes before the modules go to sleep. Make sure the hood lamp is disabled, dont open the doors, make sure the key is off. If it doesnt drop to less then 50 ma in 45 minutes, I would then start yanking fuses, remember dont open the doors, or turn on anything electrical, or you will have to wait for the modules to go to sleep again!

[Jeremy airjer W]

Essentially what you are doing is using your multi meter as the connection between the battery and the vehicle. The vehicle needs to have the constant power source so that it can complete its power up/power down tasks. Leaving the battery disconnected will do nothing and as soon as you hook up the multi meter it will go through the "power up" process.