Found transformer resetting power every time there was a call for heat. Usually this happens when there’s a high amp draw, which would normally pop a fuse but no fuse was popped. We were here last week. Fuse was popped. Couldn’t find where it was coming from. Disconnected all wires to the outdoor unit, except red and common and the fuse would pop. The only thing left with is that there is a dead short on the board must be replaced the defrost board. Replaced defrost board found burn mark on back of defrost board. Went ahead and checked wires inside the outdoor unit to see if I could find anything that would cause a short. I couldn’t find anything. Started system up. Everything ran good.