I would test probe both sides of the fuse for 12v and work my way to the switch. If I get power in, I should get power out.

I would then test probe the wires at/or close to, the bulb. I should get
power there.

When power comes out of the switch, but doesn't get to the bulb, it is usually a break in the wire.

I have had a lot of import electrical lighting problems come in lately.
Sometimes as a result of what a previous owner had someone else do.

What was the last thing you did electrical-wise just before the lights quit working?

Let us know what you find.-Bob