Welcome to the forum. In my local travels, I came across a 71 or 73 HiLo. The people want to sell it. I borrowed their literature and made a copy of it. They say it is a 1973 but the info from the paperwork says it is a 1971. At any rate, here is some electrical info on it. The manual does not show any actual trailer wiring, only the hookup from the trailer to the tow vehicle. The coiled cord has: Brown - Hot line (charge line), White - Hot line (to 12v lights), Black - Right turn light, Yellow - Left turn light, Red - Tail & marker lights, Green - Ground, White - #10 - Brakes. Hope this helps. I will try to scan that page for you.
2014 FR Heritage Glen 282RK
2013 F250 HD 6.7L Diesel
Formerly Owned: 1995 22D Fun Chaser & 2901L Classic