Never mind. I found the problem.
It was unbelievably simple. So simple, I’m embarrassed to say what it was.
Doing a quick search turned up all kinds of things that could be the issue, but in the end it turned out to be the horn fuse was blown.
I didn’t know the interior lights and the horn were connected to each other.
I rarely use my horn, so when the lights went out, I didn’t think to check the horn fuse.
Why would I?
Well, thanks anyway. I’ll post again when something else breaks and I’m too impatient to dig a little before asking an unnecessary question.
T