The number 32 fuse controls several things. One important thing is the odometer. Without pulling the fuse, the odometer will rack up miles, the nav system remains active as does the radio. Even with the radio off the nav and radio system are linked and run through the same computer system as the odometer. That's why you can't program the nav system while you're underway...I installed the toggle switch so the fuse doesn't have to be pulled. Install the toggle switch and tap into another power source for your braking system, and you'll be in high cotton.....Dennis