So in my 2013 Expy the front a/c blower goes to the lowest speed when the rear hatch is opened or shuts off. Shut the hatch and restart the car and the a/c and blower work fine. Is there an interlock relay somewhere that kills the blower when the rear hatch is opened? Rear a/c works fine. I have already changed the blower resistor about 4 times over the life of this car. Anybody got any ideas?