Harness wires connect the power cord block to the line side of the relays and also connect the load side of the relays to the back of the terminal strip. Harness wire kits include all necessary red lead wires to replace your current wires. Why do the replacement harness wire sets have yellow electrical connectors and the old ones have blue connectors on the relays? All new harness wire sets use 12 Gauge wire rather than 14 gauge wire. If your kiln has light blue connectors on the harness wires and they show any signs of wear (corroded connections, discolored wires or burned connections) you should replace your harness wires with a new set of 12 gauge wires. The larger wires will help extend relay life by keeping them cooler. Will these harness wires fit my kiln if I have black relays or clear relays? Both black and clear case relays use the same harness wire sets. For information on the different types of relays please review this document. Changing out your harness wires may necessitate changing your relays as well. Repairs and Maintenance - Kilns - KM Wiring Harness Replacement Skutt Part Number / KPS Part Number Single Phase2564 / 1000133
