Using Aux switch power to charge lithium batteries

[Yardbird54E]

Newbie here needing advice- I have a 2020 Ram 2500 with the aux switch option installed and was wondering if I can use the power from the switch bank to power a DC/DC converter for charging lithium batteries. From what I can see on the schematic on the Ram website it appears I can get 40A from the switch bank or 20A from a pre-wired blunt cut circuit that terminates at the rear frame. Has anybody used the aux switches for this purpose? Most of the resources I've seen online use a dedicated cable wired directly to the TV battery with an inline fuse or breaker. It would be nice to use the switch for control of the charging circuit.

[Gtx Eng]

Newbie here too, so this is most likely the blind leading the blind, but on my 2017 Ram, I had a full bank of Aux switches factory installed for no specific future purpose. I would think to pull that amperage, you might use them to switch a relay in the engine compartment. Is that what you are considering?

[Yardbird54E]

My thought was to use the power output from the switch bank that is located under the hood and run the hot wire from there to the rear of the TV and run a short ground wire to the ground point on the frame at the rear of the TV. I would combine the wires in an Anderson connector that would connect to a corresponding connection from the AS that hooks to a DC/DC charger. From the upfitter schematic the switches are fused at 40A but allow a max output of 28A continuous which should work with a 20A DC/DC converter. With the lack of responses to my original post I have been doubting if it's a practical idea or not. Or maybe I should have started it in the solar/battery area? Thanks for your response.