Blowing tail light breaker

[RyanC]

2007 freightliner century cat c15
Complaint: tail light breaker getting hot and shutting off. Said it only happens after about 45 minutes to an hour with trailer hooked up. Has new headlight switch, new breaker, and a bunch of other random wiring and connectors people replaced on a wimb. And the truck to trailer wiring all has been replaced. Truck hauls a different trailer every day and its same with all.

So I got it today after a 30 minute bomb tail with all lights and accessories turned on. The breaker wasn't hot, so I pulled it and put a wire in place and took an amp reading, 3.8 amps on a 15 amp breaker. Reinstalled breaker and shook everything around hooked it up to a trailer with all led lights and it only went up to 4.4 amps. While I was poking around the b+ terminal on the fuse box burned me a little. So I shut everything off pulled the b+ feed wire and nothing looked bad, cleaned it and reinstalled it checked all voltages on posts and at all fuses all reading 13.8 to 14v so I checked amperage on b+ terminal and it was around 20. Let it run for a while and nothing got hot can't find any problems.....

Anyone have any experience or issues with any of these things? Nothing in anything I looked at gives me a direction to chase for shorts or anything.