I have had this issue off and on for almost a year. I park the truck, 07.5 deisel and then a day or so later the batteries are near/ or dead. Two new batteries last fall and it did the same in late Oct while at the dealers so they cleaned and tightened pass side battery cable. We went on a trip and put on 11,000 Kilometers with no trouble. Moved the truck Sat and then Mon batteries dead again. I charged them and started the truck. Battery gauge showed just over 9V and did not start to climb for a good min to 2. When I had it in in the fall I asked about the gauge readings and was told it was normal, I have never seen a volt gauge low just after starting. I wonder if the alt is going and causing a discharge through it. I am now 4000Kl out of warantee. My buddy sugested that I remove both battery +s and connect a light between the main + post and the main cable to the starter and see if there is a drain from something, and if so start removing fuses. Before I go through this any ideas? Also does anyone have a reference as to which fused circuits should be live without the key on? Thanks and good day.