Lighting Connection on MRC decoder in Athearn F7

[Skip1001]

 I purchased an MRC sound decoder that drops in to Athearn F7's. The diagram shows how to connect the wires for the headlight and mars light, however they show simple single diagram and there appears to be 2 wires coming out of the headlight and 4 wires our of the mars light. If one wire from each light goes to a common connection, how do you know what wire from each light is to be used for that purpose? The wires are twisted into threes and connected to two connectors on the original board. Any help greatly appreciated.

[CSX Robert]

Skip1001

If one wire from each light goes to a common connection, how do you know what wire from each light is to be used for that purpose?

If they are light bulbs and not LED's, then it doesn't matter because they are not polarity sensitive.