Blower Motor won't stop.

Hi,

I have a 2009 Armada SE the other day I turned off the A/C all the controls turned off but the fan switchedover to the floor and is blowing on high. If I turnit back on it will switch to any location I choose and the temp. will change to whatever I choose but it won't shut off until I turn off the truck. Please help, Thank you.

Rommel