Performed AC diagnostic on 2014 carrier system. Upon my diagnostic client stated that nest was displaying Y wire connection issue. Started off by jumping out thermostat wire is directly at thermostat and wires immediately sparked when this happened. Also try to jump it out directly at the circuit board and the fuse instantly popped. Isolated condenser wires coming from outside and try to jump system out again infuse would not pop any more. This led me to the outdoor contactor and found that the low-voltage coil has gone bad which is the reason why the fuse in the attic keeps popping. Also during my inspection I found at the duel secondary motor control has become weak on the fan sideterminal due to the condenser fan motor leaking oil from the bearing And using more power than needed. Informed Chris what is going on with the system and presented him repair options for a long-term solution. He authorized of the best repairs done. Also sign him up on maintenance plan for two visits a year