Same here Dave, except I used a 7 pin unit so I could run power to charge a battery in the trailer. I also used an isolator harness so I am not putting a load on the bikes lighting system for the trailer, the isolator uses a direct link to the battery (switched on and off with power) and the lights turn on and off relays in the isolator,
The 7 wire system I use is RT Turn, Left Turn, Brake, Running Lights, Lighting Ground, +12V for Charging, Ground Line for Charging. I probably could have used only one ground but I didn't want the charging circuit to affect the lighting.
The wiring is standard except I use the "Electric Brake pins" as my charging circuit. I put a relay powered by the AUX connection on the bike to cut power to the trailer when starting or when turning the bike off. There is a 30 Amp fuse inline with the relay to protect the bike any issues with the trailer..
Henry.