CONCLUSION- Here's what I've decided to do:
I didn't wash the entire engine, so I don't think the problem can be attributed to any wet wires, etc. Also, the radiator fill is positioned in such a way that no coolant was spilled on the engine, so I don't think that's what's causing the burning smell (I wish it was--it would make things a whole lot simpler for me). However, the burning smell is exactly the same smell that came from the engine compartment after I'd driven down a gravel road and gotten the radiator covered with dirt. Although the radiator looks completely clean now, I'm going to start by taking a hose to the outside of the radiator to see if there is fine dirt that may be causing the burning smell.
I called Monaco & they have doubts that the "check engine" light is due to flushing the radiator. As a precaution, though, I'm going to re-bleed the system according to the way Monaco told me to bleed it. I've also gotten the name of a reputable radiator shop in Naples, FL, that I can take the RV to if need be.
Unfortunately, the nearest Cummins is in Ft. Myers. If the burning smell continues, I think that Ft. Myers is going to be too far to drive it safely. Therefore, I'll see if there's a full service shop in Naples that can have a look at it in the event that the burning smell & "check engine" light issues continue. Thanks to all for your help.
