Because the dash A/C heater system is a cross over , ( powered from the chassis ignition system but installed by the coach manufacturer) wiring diagrams can be difficult to follow ; or non-existent.
Have you seen the names ; Evans or Denso anywhere on the dash systems components, they are the common suppliers of the dash systems, and a wiring diagram from them may help.
I'll describe my dash system, ( and supplier/installer of parts) power set up and maybe it will help.
The ignition switch, ( Freightliner) , powers up an ignition system relay ( Newmar), the relay powers an in-line 12v circuit breaker, ( Newmar) that supplies the dash switch ( Evans installed by Newmar) . The dash switch supplies power to the fan motor through a resistor block that controls fan speed ( Evans ) and through an A/C low pressure sensor ( Evans) back to the chassis wiring harness ( Freightliner ) to power the compressor clutch on the motor , ( compressor mounted to the motor by Caterpillar).
Complex enough for you.
I'm thinking that some where , between the ignition switch and the dash fan switch you need to find an in-line fuse, that was blown when you had the wiring disconnected.