Volvo VNL 760 Electrical Issues at Trailer

Looking for identification of each pin where pig tail plugs into trailer.

And would like to have a list or schematic for each fuse and relay in the dash of the truck. I know the general fuses are identified on the under side of the fuse cover, but what about each relay and the larger fuses in the center and the fuses to the right side? Just as many are not marked as there are those labeled.

Issue I'm trying to fix: 1/2 of the trailer marker lights are always on when the truck is running and the light switch is off. It was suggested to me that the ABS line might be mixed up either at the PINs at the front or maybe shorting in the junction box at the rear.

Also, right side tail lights come on and go off. I had a volt meter on the relevant post inside the junction box and watched the voltage go from 0.0 all the way up to 12.0 and climb back down. It was suggested that a relay may be heating up then kicking off? Yes, no, maybe? If this is the case, could the relay be good and doing its job but due to the other issue, some lights always on, that the relay is getting too much work?