I don't have a Golden Arrow schematic but this is from Big Hit earlier the same year.
Big Hit score motor (resized).jpg
Sounds like the wire colors might be the same although beware that the relay switches might not be. If you unplug your game and clip your meter to to the yellow+red and red-white wires your meter will tell you the resistance between those points. The trouble is you can't know what path(s) the meter is measuring. If all the switches are open the meter is measuring the combined resistance of the path through the score motor, transformer, fuse and bounce switch which is probably somewhere between 10 and 50 ohms I'd speculate. If one or more of the switches is closed you should see a resistance of an ohm or less because a lower resistance path is available. The meter still sees and includes the other path in the measurement, but the lower resistance path through the closed switch overwhelms the higher resistance of the path through the motor and transformer.
In this case you can simplify the measurement by disconnecting the motor service jack to take the transformer path out of the equation. Then you're left with just the paths through the various switches. Any one of those switches closing should drop the resistance to an ohm or less and the resistance should be open circuit if they're all open.
Beware that one of those switches is on the AX relay which is an interlock relay. So the switch could remain closed even with the game unplugged since the interlock relay can lock in either position. Check to make sure that the AX relay switch is open.
Once you have the score motor disconnected and an open circuit measured between your probes, you should be able to manually activate any of the relays that have a switch in the circuit (C, G, J, P, etc.) or the score motor to close a switch and the resistance should drop. I suspect that your score motor 1C switch won't drop the resistance measurement as much as the rest of the relay switches because something is going on with that switch. But test several of the switches to compare their resistance measurements.