I an trying to install a honeywell 360 humidifier on a Trane xb90 furnace. I have completed the installation but the sail switch does not operate very well causing my considerable distress.
I would like to wire the control for the humidifier to the blower on the furnace so that when the blower kicks on the humidifier will follow suit.
I do not know which wire to tap into to allow this operation.
Any help is greatly appreciated.

Does that furnace have a smart motor. IF so you can't use the motor to power the humidifier. The PC board should have humidifier terminals on board. See furnace documentation for more. There is over a dozen ways we wire humidifiers depending on the furnace and humidifier.

I looked into many things and ended up wiring a plug off the blower (120 volt) , then simply plugged the humidifier into that so when the blower is directed to turn on for the heat it will run the humidifier
Thanks