Dead Batteries on my 2000 F350

[rtown1962]

I have a 2000 powerstroke diesel that I drive once or twice a week. I am experiencing problems with something draining my batteries. The batteries are practically new (850CC), but after sitting for several days, they are dead as a door nail. The power doorlocks want even work, but after a 30 to 45 minute 50 amp charge, the truck runs, and start fine. I also noticed a clicking sound or something running under the dash, but the truck will not attempt to start at all. Can someone point me in the right direction to start troubleshooting this ongoing problem. I have replaced several batteries that are still under warranty, therefore, I don't think I have a battery issue, somethings draining the batteries with the ignition switch off.

Ron

[bevansracing]

on my old truck the gem module under the dash was killin the batts