12 Volt Mystery After New Batteries 2020 Navion 24V

[BobJH]

After changing out the original house batteries, 12v is no longer available in the coach for lights, etc. However, battery power is available at the inverter. I suspect the problem may be with the "Coach Batt" switch. Nothing happens when "ON" is selected. I removed the access panel under the sink to look for an inline fuse. I saw only one, a good 2a fuse that looked to be for the floor level light. Is there a fuse somewhere else? Is a relay built into the switch or is one located somewhere else?

If anyone has some advice, I would it. Thanks

[Eagle5]

I see on page 6-8 of your Owner's Manual, the coach disconnect switch should always show a green light, be it switched on or off.
It could be a high-capacity fuse (either 125 amp or maybe 175 amp). This posting talks about something similar going on:
https://www.winnieowners.com/forums/...ml#post3919510
But why would the inverter still work?
Can you get some voltage readings at various places?
Thanks, Eagle5