60 amp BTN fuse on 2000 Mazda Millenia

what is the BTN 60 amp fuse for? Its pulling my battery down when the car is off.

Asked by for the 2000 Mazda Millenia
The 60 Amp BTN fuse is live when the ignition switch is on bringing power to the ignition switch. Circuits that are live with fuse in circuit are the 6 other circuits, to identify which circuit is causing the drain disconnect on at a time the 5 Amp Hazard fuse preferably using an inductive amp meter around the battery negative cable see if the draw goes away. The next circuit to check are checked by removing one at a time and seeing if the draw goes away, 30 Amp door lock fuse, 20 Amp brake light switch, 30 amp air conditioning condenser fan fuse, 15 amp dome light fuse, I think its marked room, and finally the 15 amp fuse marked "opener".
What does the BTN stand for and what is its function I have a Ford Probe 1993 That when that fuse is in its shorting/grounding the system
can u answer the Question for the BTN above i would also like to Know