Batteries going dead

[hvp]

I have a 2004 E450 with a 6.0. The truck has new batteries. When the truck sits a day or so, when turning on the ignition, the voltage guage just drops down to next to none. Most likely due to the glow plugs. The starter just ticks. If I plug the truck in, the guage dips a bit and the truck fires right up. I can drive it all day, re-starting numerous times and it cranks over fine. It appears to me that there is a drain of some sort. And maybe the guage is dropping off because of the demand from the glow plugs on low batteries? Is there anything obvious to check? Is it a ground or something like that?

Hope someone can help
Thanks, Alan

[raisemhigh]

alternator....i replaced both on mine. did the batteries first, did ok for a lil while, then did same thing yours is. Replaced the alternator...and been good to go ever since

[hvp]

Thanks for the reply. The glow plugs seem to drawing a whack of juice. When it is warm and the glow plugs are not needed, it seems good. However when it sits, plugged in or not, there is little or no power. If you think of anything...

Thanks again. Alan