My 2004 35E has an Onan Generator already installed.  I sometimes camp where there is no power and we stay for multiple days.  Instead of worrying about my house batteries going dead while we were out cause something got left on or spending a lot on solar equipment, I decided to add my own auto generator starter.  I found an Onan Energy Command 30 from a local electrical supply company.  I ordered it and the pigtail harness.

This controller will monitor the house batteries and the vehicle battery.  If either get down to a set voltage the generator will start up and run till the batteries are charged.  It will also kick on if you are plugged into camp power and the power goes out.  This is great if you have pets and its hot out and the campground for some reason looses power, your A/C can still run to keep the coach cool.  It will also monitor the thermostat if you are not on camp power and you want to run A/C but don’t want the generator on all the time, it will only start the generator when the thermostat commands a cooling cycle.

Once I received my controller it was time to run some wires.  I bought a spool of trailer wire since it was available nearby, the right size and bundled together.  I ran wires up to the front of the coach to the power distribution center for the vehicle and house batteries. I put inline fuse holders at the front to protect from shorts.  Another wire went up to the parking brake wire so the system would only be armed when the coach was parked.  Another set of wires were run down to the generator control plug.  These wires are the ones that run up to the factory start/stop switch on the dash.  A couple more wires were run up the the back of the circuit breaker cabinet.  These wires go to the ECC controller for the A/C command and two more wires go to a 110V to 12V transformer to monitor if there is camp power.

I’ve included the wiring diagram for my application and a picture of the control panel which I mounted below the ECC panel.