Congrats on the "easy" fix! You can use this escapade as a good lesson in troubleshooting, a talent that comes in handy when using an RV. Know that everyone starts from where you are, and hopefully progresses.
1. Always break a problem down to its smallest element. Once you get over the shock of "it don't work", see what else works, and what the exact failure mode is. Be sure to tell the Forum about the failures, even if they seem strange to you. Sometimes a seemingly unrelated thing can be the "smoking gun" that points out the solution.
2. Get a multimeter for testing
12V and 110V circuits. My favorite also happens to be about the cheapest available, the Harbor Freight $5 model. Sometimes they even give them away, just for showing up in the store to buy anything!
3. Count yourself lucky that your AC failed properly, and didn't go intermittent! That's the worst as it makes it harder to troubleshoot.
4. Remember that "smoking gun" I described earlier? Don't rely on it too much, as more than one thing can fail at once!
Kudos on you posting the solution! That is the Law of the Geek; when asking a question of an expert, you must always follow up with the solution, no matter how personally embarrassing it may be!