I decided to put my Zumo 660 on a switched power source. After buying the BMW 3 wire GPS connector ($20.00) I connected it to my GPS and added a 1" voltmeter. Works great, gps turn on with the key, and shuts off about a minute after the key is turned off (its a canbus thing). Only thing is the voltmeter is only reading about 8-9volts, shut off or running. I tested the voltage with my portable voltmeter and got the same readings. Directly off the battery I am getting 12+ volts not running or 13+ volts running. Is this normal???????