Blue Wire from truck to trailer in light cord always hot

Working on a 2013 Freightliner Cascadia Blue wire to trl always hot. With ignition turned off still power to trailer. I have checked all relays and pulled all involved with the ABS power still continues. If I pull the relay for "trailer Power" then no power . I have replaced this relay problem not corrected. I have disconneted the harness off the ignition switch ,from the ABS ECU still has power . I have followed the blue wire to it's connection at the fire wall and pulled out the connection . I chercked the terminals coming from the fuse box and it is hot. I have run out of ideas except to pull the fuse box on the firewall apart and check the wires going to the relay. Hoping for some help !! Possible the power is feeding from some where else . Thanks In Advance

 

I wasn't sure if the SAM module feed the ABS ..The Sam is located under the fuse panel at the glove box ? Thanks for your reply !!

 

OK Thanks didn't realize were the relays and fuses are is all part of the sam chassis . This would still need to be programed by Freightliner ?

 

Driver said not performing self test properly . Due to the fact there is constant power supply to trailer from tractor . When turning ignition will not power up and perform self test., because already hot. I have 6 of this and this is the only one . Hauling hazmat I'm not sure there should always be power running to trailer when sitting.

Thanks again Quality truck there was a green mess in there clean it up works good.

 

Thanks Rocket Man Good diagram