Toad tail light wiring

I was in exactly the same situation and wired the dinghy to use the separate brake and turn lights. As another post pointed out, the trailer connector will likely be wired for combined turn/stop lights. In my rig, they use two relays for each side to combine the stop/turn lights, which are separate on the chassis. I had to change the relay-logic circuit in the motorhome, use the aux line in the 7-pin cable for the extra brake light line, and had to relay the dinghy brake lights because the chassis computer senses too much current if the dinghy's bulbs are driven directly. I would have been extremely difficult to do this without wiring diagrams for the motorhome and dinghy.

If you just let the Odyssey's brake lights act as combined brake/turn lights, it's most likely the trailer connector is already set up for that. You just need to add an extra bulb or go the diode route.