IMHO, crimp connectors are designed to minimize costs in high speed production environments. In this application, where the seat rotates and moves up/down, the use of a crimp connection is a prescription for failure. I believe that the problem with my wiring was related to the quality of the connector AND the skill of the technician. My final solution was the use of lightly soldered connections and the proper size of twist-on connector for the heavy gauge wire. Before I put the wires back inside the Velcro jacket, I reinforced the connection by applying small 4" cable ties to the wires and the connectors to protect them from axial stress. See example photo...