I can't find where to connect trailer light harness bought from harley but there is no instructions and I can't find how to hook it up

There should be a plug on the right side of the bike under the seat at the back where the fender starts. I think you have a pig tail that just goes in between the male and female plugs on that part of the harness that goes to your tail and signal lights. If thats not good enough I'll check at the shop tomorrow. There should be a plug on the right side of the bike under the seat at the back where the fender starts. I think you have a pig tail that just goes in between the male and female plugs on that part of the harness that goes to your tail and signal lights. If thats not good enough I'll check at the shop tomorrow.