WARNING: This page is about a different car, the 2006 BMW X5, 2005 BMW X5, and 2004 BMW X5. However, it is still accessible from the selected car via links, so may be relevant.
64 12 ELECTRIC AUXILIARY HEATER TIGHTENING TORQUE SPECIFICATIONS (1AZ)
Type
Thread
Tightening Specification
Measure
1AZ Battery positive and negative leads to auxiliary heater