I would suspect one of several things.. The blower fan motor is drawing too much amperage and when you turned off and back on, the draw caused the VBC to blow. I remember years ago (I think it was in the early '90's), Nissan had a bad run of blower motors that were drawing excessive amperage and burning out the blower resistors in the Sentras. Less likely, I would consider a poor ground circuit for the VBC or a faulty HVAC controller. If I was going to replace the VBC again, I would definitely install a new blower motor, as well.