If you found the right relays, the diagnosis is fairly easy. Use a voltmeter to see if you have power to the relays. There needs to be two hot wires there - one large one that supplies 12v power to the coach (Aux relay) or chassis, and another small one coming from the switch for each. The small wire has power only when the switch is on. The relay itself may provide the ground for the small switch line, or there may be ground wire. If both wires have +12v, then check the large output wire for +12v to see if the relay has indeed closed. You can use a battery jumper cable to bypass the relay to see if that provides power to the coach. If it does, the realy is the problem.
2004 American Tradition; 2014 Buick LaCRosse
Homebase in the Ocala Nat'l Forest near Ocala, FL