Truck went dead today after sitting at work, It has new batteries and they were completely dead after work,
If it is a bad ground can this drain the batteries that fast?
2004 3500

I doubt a ground but a short or a module that did not turn off. I would get each battery tested seperately. Even new batteries go bad and if one is bad it can take the other with it. If warm weather then unhook one battery and see if it holds charge. Then try the other. Other test is connect a light bulb between the battery plus cable and the plus on the battery and start pulling fuses till bulb dims to see what is pulling power. Or use am ampmeter.

Brian

I doubt a ground but a short or a module that did not turn off. I would get each battery tested seperately. Even new batteries go bad and if one is bad it can take the other with it. If warm weather then unhook one battery and see if it holds charge. Then try the other. Other test is connect a light bulb between the battery plus cable and the plus on the battery and start pulling fuses till bulb dims to see what is pulling power. Or use am ampmeter.

Brian
I charged the batteries today and load test and they are good. I dont know were to look for this problem. Can you explain the light bulb test a little more.
Thanks Steve

It is possible that the alternator is not working. Simple check: put a voltmeter across one of the batteries before you start. Should be about 12.5 volt depending on the accuraccy of the meter. Start the truck. Should go up over 13 volts. If it goes down the alternator is bad. At that point it had to die someplace and it happened after it sat in a parking lot.
Worth a quick try.

It is possible that the alternator is not working. Simple check: put a voltmeter across one of the batteries before you start. Should be about 12.5 volt depending on the accuraccy of the meter. Start the truck. Should go up over 13 volts. If it goes down the alternator is bad. At that point it had to die someplace and it happened after it sat in a parking lot.
Worth a quick try.
The alternator is showing 13 volts on the batteries and the gauge in the truck shows 14 volts.

If I leave the batteries hooked up I can watch the voltage go down.

Asuming you where running and seeing 14 volts that alt should be fine.
To watch a voltage drop is a major power draw! (Again, assuming that the drop is as soon as you turn it off...) That would equate to something like 100 amp draw similiar to a battery test station. The only cables big enough for the kind of draw are the starter cables! Anything else would glow red for a while and go puffffffff.... (Unless you have added something else with big cables....) Check those cables to see if they are rubbing the frame or block somewhere before the starter....

could be the Glow Plug relay stuck or the Intake Air Heater relay stuck.
They are possible to stick once in a very rare while then they completely drain your batteries. They are both in the same GLOW PLUG CONTROL MODULE.

I would disconnect the passenger side battery. Then remove the positive terminal of the driver side battery and wire a light between the plus wire and battery plus terminal. If pulling it will light up. As you pull fuses heavy loaded ones will make the light dim.

Brian

Tanc, Your procedure would work well to find small current draws of less than 20 amps. Anything more than that will blow your test bulb. The stuck glow plug relay pulling up to 175 amps makes sense since he can see the votage drop while watching it.
It must really arc when taking the pos terminal off.....

Yeah your right on that. I would hope it not pulling that much but your right if dead by morning it is pretty big draw. I bet it does arc good too.

Brian

What I've done before is disconnect the battery and hook up a battery charger to the + and - cables and watch the amp meter. Any draw will show up on the meter. Then start pulling fuses one at a time till you find the circuit that's drawing juice.