How long does it take for a mechanic to check fuses and relays?

Hello, maybe an hour. I use a test light, hook it to battery negative and check a whole fuse box in a couple of minutes, if there's a problem found, that's a different story, but for just inspecting fuses and making sure everything is okay, it does not take long.

https://www.2carpros.com/articles/how-to-check-a-car-fuse

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit