Alco 2-6-0, Model H517X (8 Wire Connections From Engine)

[russ daley]

Troubleshooting a "go then, then stall, then go" issue and after trying everything I know to resolve have decided to remove circuit board and hard wire. It's not my first hard wire so I feel confident when I attempt to do so and will most likely find out once I start confirming what each wire does but I"m use to 6 wires (2 light, 2 rail, 2 motor) coming from the engine not 8. Can anyone tell me what the other 2 wire are for before I dig in?   

Thank,