My brother has a 99 sd 250 7.3 4x4 with a intermittent battery problem. for starters - it has two brand new red top optima's. At any given time (could be over night or could be two weeks) the batteries will be completely dead. The first thing we thought of it could be is the alarm/remote starter. we unplugged it and problem still there Second thing thought of maybe glow plug relay disconnected that problem still there. If anyone might know the next thing to try please let us know. I'm leaving tomorrow for the weekend so I won't be able to answer any replies till Monday evening. thanks in advanced.