Battery Problem - They keep discharging

[Pawpaw]

You could put a battery disconnect similar to this one on one battery:



http://www.northerntool.com/webapp/...Display2?storeId=6970&productId=13317&R=13317



Open the switch and then use two trickle chargers to keep both batteries up to snuff.



This is the charger that I keep on my wife's car. It has no problem maintaining the battery with it still hooked up.



http://www.northerntool.com/webapp/wcs/stores/servlet/product2_6970_197012_197012



Bob

 

[jelag]

I have an 04 that I keep a fridge in... . during the summer... . this thing draws 5 amps when it runs an cycles off and on... my 04 will start after 4 or 5 days of being left alone with this thing running all that time.....



I see you doing one of several things but they all are based on understanding amp meters and how to test for a draw... . A number of years ago I looked at a car for a friend that kept running the battery down and it was nothing more than his wife putting the litter bag on the cig lighter when she drove the car... . it would hang and try to turn on the lighter and it would draw the battery down over a day or so... when hubby drove the car, it got in the way so he set it on the floor... and no problems... .



Take the neg battery post off one battery. . on the other battery either install a clamp on DC amp probe or a DC amp meter in the circuit..... look for a draw... I can tell you that to run these batteries down overnight would require at least a 10 - 15 amp draw for 5 to 7 hours... ... maybe longer depending on the condition of your batteries... . If all you see is less than an amp... you either have a bad battery or something that is now drawing current now... something that is not running, etc. .



Also if you've changed the batteries and have a BAD one... one that is shorted internally you'd start to run the batteries down as soon as you turned off the rig and might not correctly charge the batteries when the truck was running... . based on problem with the batteries... . I'd go see the guys you bought the batteries from first and check them out...



My son had a problem like you with a Pontiac Van... . it was driving him and me nuts for 4 or 5 days but I finally got him to pull loose 8 or 12 of the ground connections and clean them... . put them back together with some light dieletric grease on them and his problem went away and didn't return, but we never decided which connection was the bad one...



I know a good electrical shop can find this problem but you need to find one in your area... I belong to an association of guys and part of our group are some of the best electrical guys in the country... I've never tried to use any of these guys for this kind of need... but if all else fails I'd try to hook you up... . Understand that I've read some of their technical stuff... . and know that they can work hours on a vehicle to really test and understand whats wrong... and the customer pays for all that. . what they don't pay for is all the parts that a dealer might try and and not take off...



When I was working in the equipment field... we had a phrase... ""test, don't guess"" and I can't tell you how few techs I knew... I've personally spent hours working on cars finding and correcting the screw up made 6 weeks ago... and 10 guys have missed... . but listening to the customer and testing would finally find what is wrong and fix it... .



BTW if you don't find a fix... I'll give you $1000 bucks for your truck... . Good luck. .

 

[Mel Swanson]

Lamber

I came to TDR for the same problem several years ago. As it turned out my power problem was that the battery was not charging enough to maintain enough power to do its job. The fix was too tighten up the battery cable where it attaches to the frame. Good luck.

 

[sag2]

I'm getting into this a bit late but think I can add something that might prove useful. These trucks have many modules that "go to sleep" when they are no longer being used. When you turn off the key and get out of the truck the modules start dropping off the bus one by one until they are all asleep. Then every minute or so certain modules "wake up" and take a look around the bus to see if they are needed. Each time one wakes up the current will spike up somewhat and then drop back off to below the 35ma ign off draw spec. In order to test, use one battery as mentioned earlier and you need to start with a meter (not a test lamp) that is capable of carrying at least ten amps. Hook the meter between one battery post and the cable and start measuring the current draw. It will start at several amps and you will see it drop as modules drop off, usually within one minute or so. Also make sure the key is out of the ignition, and you have the door shut and do not open it until your done testing. Work through the open driver side window if you need to get inside the truck. Start pulling fuses one at a time waiting a minute or so between fuses. Remember it is normal to see the current spike for a second as long as it drops back to normal after a second or two. If it spikes and stays up, that means the module thinks it needs to stay awake, and it will continue to pull current.

Got to run, but I might add some more when I get back.