My Landcruiser is draining electrical current with the ignition off. The 12V cigarette lighter stays on, the Navigation/systems monitor starts to power up intermittently with the ignition off and the battery eventually goes dead if I don't start the rig and drive it before the battery loses too much voltage. I have had this happen three times now but before I can figure out the problem, it goes away for a few weeks...then comes back. I'm at a loss. Please help if you have a direction for me to take this to resolution.