Your MH may be different but my battery disconnect switch is momentary and goes to a relay. So touching the tow wires together should toggle the relay. Touch once and battery is connected, touch again and battery is disconnected. Since you've already installed another disconnect switch just "make" the relay and then leave the wires disconnected.
2015 Greyhawk 29MV
Honda CRV toad with Blue Ox baseplate
Ready Brute Elite towbar with braking system
TST 507 Flowthru TPMS