I don't think anybody can paint a clearer picture than Darl just did. Our coaches have to be respected and I can think of a number of things as owners who work on them we have to be aware of.

Obviously spring brakes must be respected. But if you are contemplating getting under the coach make absolutely certain it is properly supported under the chassis support points. It doesn't matter if you are merely going to be under it for a second or two. Don't do it without the coach being supported.

Stay away from exposed belts when the engine is running. You will not stand a chance if you wear loose clothes and get caught in a belt.

Don't under any circumstances work on an inverter unless you are 100% sure you have removed not only 120V power, but the 12 or 24 volt circuit to the batteries has been disconnected.

I'm sure others can suggest more things to be aware of, but those leap out at me as biggies.