When wiring relays for a reversing polarity door lock system, which terminal connects to the motor side of the cut factory door lock wires?

In a relay system, the correct terminal that connects to the motor side of the cut factory door lock wires is the common terminal, which is terminal 30. This terminal serves as the point where the power supply is connected and maintains a connection to the load — in this case, the motor in the door lock system.

When implementing a reversing polarity door lock system, it’s crucial to understand how the relay functions to control the current flow. The common terminal (30) connects to the load or motor while the other terminals control the relay's activation and the direction of the current flow to enable the locking and unlocking action.

Using terminal 87, for instance, would typically be reserved for output to the device being powered under normal circumstances, while the control side of the relay, involving terminals 85 and 86, is for the activation of the relay itself. Those terminals handle the switch operation that allows current to flow through the common terminal to the appropriate load.

By connecting the motor side of the cut factory door lock wires to terminal 30, you are ensuring a solid connection that allows the relay to effectively control the motor based on the polarity switching.