Within a week of purchase in 1995 (I bought the truck new and I was the only owner), the batteries died. I took it back and the dodge dealers replaced the batteries. That set last a month before the batteries failing again. Took it back, and the dealer said that both batteries were dead again, and they were replaced again. The did a system check and couldn't find anything wrong. Within a month, the batteries failed again. This time I called Dodge and told them that this was a significant problem and if they couldn't fix it they could replace the truck. They sent out an " expert" to look at the system and he checked it and couldn't find anything wrong. They replaced the batteries again. To this point I had been using Dodge batteries. That set worked 5 years. Then I replaced the batteries at Sears. Those batteries ran another 5 years, so I thought the problem was gone. Recently, I replaced the batteries again, and they died within 2 days. You took them back to Sears and they tested it and said that one battery was dead and the charging system was fine. If I run them within a day, the batteries are fine, it seems, but if I just let it go, the batteries die. They've died twice, recently.
So, the first time they dies, I hooked it up to my battery charger. When I went back to check, the charger had fried. The charger was connected correctly, leading me to believe that there was a short and has been all along.
I'm wondering if its the glow plugs. I've never replaced them - if that matters. The truck has 137K miles. Hope that's sufficiently detailed, the truck is outside (60 degrees), and dead.