There have been a number of posts asking for help to troubleshoot a failure of the engine to turn over and others even though it turns over will not start, by some new Safari owners. While there are differences between RV models the principles are common.
Power from the ignition switch on the dash usually engages a relay/solenoid to provide high amperage current to a bus bar distribution system. The engine starter on the pushers are supplied power by a solenoid activated by a sense wire from the key ignition. The current draw is far to high to run directly to the starter solenoid as it often does in a car, therefore an interposing solenoid supplies power to the engine starter circuit via a solenoid to the starter motor Bendix which pulls in the contacts on the engine starter, turning over the engine.
The following is just a visual-audible presentation of where and how these solenoid circuits work, which is the requirement to troubeshooting the problem.