I would look at the ignition wire harness side as the issue. If you pull the tumbler and turn it and the issue isnt there then someone may have changed something as no power should be to it with ignition off. Some people run hot wires and a switch to the motor to bypass the the CCU (climate control unit) and same with the A/C compressor. That way they can have full fan or full AC or both without all the systems safeties shutting it down.
Good Luck.
Good Luck.