Yeah, you'll need to look through your wiring diagrams and figure out what your coach may or may not have been pre-wired for.
Do you have spring-contacts inside your door on the hinge side?
If so, maybe your door already has a lock solenoid in it. And relays to control the solenoid... and lots of wiring in between...
But if the coach didn't come pre-wired for a keyless entry system I suspect it will not be a simple task to install keyless.
2003 Monaco Dynasty 42 Regal.