Yes, the left brush holder. The small chutes dump the coal from the hopper into the awaiting car, but the chutes do not open very far resulting in most of the coal going on the layout. You can manually depress the solenoid to open the chutes and that will allow you to see how far they will open. The wires pictured attach to a ground lug on the back of the field on the motor which effectively grounds the motor and solenoid to the frame. Removing these two wires and connecting them to a separate lead will isolate them from the frame.