My 2023 came with the snowplow and auxiliary battery packages but it is a fleet vehicle and the upfitter that put on the bed cap, amber lights and a useless inverter altered the factory wiring to add an isolator and a voltage sensing disconnect and attempt to make the auxiliary battery work as a backup starting battery. It wasn’t wired correctly and on three mornings this winter, would not start due to a drained battery.
So I ordered a new battery harness from Amazon for $127.83, took out what the upfitter installed and used this thread as a reference.
Here is the wire harness link:
https://a.co/d/cEONIcx
The pictures I am adding hope upload in this order:
Auxiliary Battery
Starter Battery
panel that sits on the starter battery
panel that sits on the auxiliary battery