What causes an air conditioner unit to blow a fuse after being replaced? on 2010 Mazda Mazda3

In 11/11 the car stalled on the highway, was towed to a mazda dealership and we were told it was the airconditioner unit seized up and would need to be replaced we just purchased a new unit had it installed and right away began blowing fuses? What causes this and how do we fix it?

Asked by for the 2010 Mazda Mazda3