Orion xs dc to dc chargers

Hi all
I’m in stalling to orion dc to dc chargers in a older grand banks, to charger my house batteries (4 life life L16s). My question/problem is with auto engine run. When not connected to shore power the system work perfectly, but when connected to shore power the start battery kicks in and charges the house batteries and the starter batteries. This pegs out the starter charge to 50 amps. I have a multi for house charging.
The question is can i plug the 12v ignition power on, to the h plug allowed to charge jumper and turn off the auto sensing?
Thank you