Trailer power buss bar behind coolant tank

[Diesel89]

2005 chn613

Hey guys on the trailer wire buss bar connected to the coolant tank bracket I'm trying to get ignition power at one of the lugs for the trailer abs. the manual list a battery constant and a ignition it also list a trailer abs but the brown trailer wire is on it 🤔 there are no lugs giving constant power any ideas?

[Mackpro]

Power comes through fuse 39 in the fuse box on the fire wall , then through  the trailer ABS relay that’s in the same fuse box . Power comes out of that relay on wire # 39-B-5.0 that goes up to the trailer buss bar, then it’s connected to the blue wire that feeds the trailer