Here is how I approach unknown wiring. Use a multimeter and set it on ohms / continuity. Find the track pickup wires by putting one probe on an unknown wire and one probe on the fireman side pickup wheels. Move from unknown wire to the next until you find the one that reads zero ohms or sounds your continuity buzzer. Then do the same for the engineer side pickup. So now you have 2 wires identified. Next, get out a 1.5 volt battery (for 1.5 volt lamps to not burn out) and jumper to any other 2 unknown wires and look for lights to go on. Be sure to swap leads on the battery in case it is an led and you have polarity wrong. If you get no lights, try a 3 volt battery doing the same thing as above. That will nearly always get the lamps identified even if very dim (incandescent). LEDs with 3 volts will light brightly unless they have inline resistors. Be sure to repeat this until you find all the lamps - forward, reverse if applicable, cab lights if applicable, etc. Thru the process of elimination you can identify the function common.
Be sure you identify all the lamps before you proceed with a higher volt battery as in the next step - if you dont, you could blow lamps with the 9 volt battery.
After you have found the pickups and the lamps, you can confirm the motor with a 9 volt battery and determine polarity by swapping leads.
You might even find the motor with just the 3 volts.
It took longer to type it out and explain it than it does to actually do it.
I have been able to positively identify my loco wires using this method every time I needed to.
Some manufacturers who I detested their on board decoders had no documentation as to the wiring and also the wiring colors are never to be trusted. I found many factory fresh locos with completely non standard color coding. They just used whatever they had on hand.
Hope that helps,
Tom Wilson
Be sure you identify all the lamps before you proceed with a higher volt battery as in the next step - if you dont, you could blow lamps with the 9 volt battery.
After you have found the pickups and the lamps, you can confirm the motor with a 9 volt battery and determine polarity by swapping leads.
You might even find the motor with just the 3 volts.
It took longer to type it out and explain it than it does to actually do it.
I have been able to positively identify my loco wires using this method every time I needed to.
Some manufacturers who I detested their on board decoders had no documentation as to the wiring and also the wiring colors are never to be trusted. I found many factory fresh locos with completely non standard color coding. They just used whatever they had on hand.
Hope that helps,
Tom Wilson