if your referring to a wire to tap into for illuminating the gauge youll have to tap into one of the many grey wires that feed to any of the ilumination bulbs....or at pin 48 of connector C1 at the BCM
the dimmer switch sends the signal to the BCM which is what regulates the voltage to adj brightness of the cluster/hvac/control button lamps/etc, etc
what im trying to figure out is where to tap into so it will be turn key to turn the gauge on but whatever source i use cant lose power when i turn it on and its says that in the instuctions for the gauge
Any accessory wire should do the trick... And if you're finicky about tapping into other wires, get a power drop harness. Has a constant, a switched, and a ground.