I have a 2000 Kenworth T2000 and mine does not have this problem. But my friend has a 2006 Kenworth T2000 and his has this feature if you leave the stereo on and the doors open with the cab lights on it starts beeping and then everything cuts off. some sort of safety mechanism to save the battery..............well this feature has stopped working and now he has no interior lights , no map lights, no dome lights. and KW parts counter does not know what this is. maybe someone can point me in the right direction as to were the module might be.