[MrE]

Mark, my 1986 has the fire extinguisher wired in.

[Mxfarm]

Thanks Jon, I can see I've got a bit more to do.

[77newell]

Do you know which what triggers the 2 solenoids. On the 77 coach I used to have a mouse got in the box excreted enough waste (putting it politely, that connectors got corroded and the engine wouldn't start.

My concern with your thinking at this point is the possibility that the controller itself is doing it's job as designed, it may be getting the wrong inputs from the sensors it monitors. Unless you can verify the inputs are working correctly you could end up replacing the controller and the generator still won't run. Knowing what the two solenoids are supposed to be doing will help figure out how to proceed.