As usual MrBally is spot on. There are clues in the schematic as well. You can see the 2 Coin Unit there, and its wiring is all dashed lines which we presume to mean it is an option. You can then correlate the wire colors to your dangling wires as shown in this pic, the Red/Black, Gray, and White/Blue ones.

There is a 4th wire there which looks like it is Black/White. I'm not totally sure where that one goes, as it doesn't seem to be associated with that 2 Coin Unit, and there are a number of different Black/White wires throughout the schematic. But I think it might go to the switch on the 3rd Coin Chute relay as shown. My guess is that this machine does not have the 3rd Coin Chute relay installed which is pretty typical I think. You should see a blank spot over there where those relays are for the 3rd Coin Chute relay and there will be some wires hanging there also, probably tucked underneath like it looks here from my Bon Voyage.

Champ 2 Coin Unit wiring (resized).jpg

front cabinet mounting board front right (resized).jpg