What do you mean when you say the plugs and wires? As that is a diesel. Maybe connectors and wiring for the safety switches?
It sounds like the seat switch is causing the problem as most interlock systems require a the seat switch to be engaged in order for the motion control and probably the parking brake to be activated/ released.
It sounds like the seat switch is causing the problem as most interlock systems require a the seat switch to be engaged in order for the motion control and probably the parking brake to be activated/ released.