[triplehorn]

I have mine hard wired to ignition source. It is always on when the key is on. If you press the right 2 buttons at the same time it will turn off the trailer tracking. The sensors on the trailer will continue to function (decrease battery power) while on the valvestem. If you want to "turn off" the sensor it will turn off when it is removed from the valvestem. The TST monitor just monitors the truck tires in this mode. After hooking up to the trailer, simply press the 2 right buttons again and the trailer will again be in the monitoring sequence.