Q: Maps can't work on a wired network?

Why not simply use the maps application without depending on it to find your current location?  SImply type in your location and maps will function just fine.

Location Services (including Maps and "Find My Mac") relies on a database of known Wi-Fi access points. You don't necessarily have to be connected to a wireless network, but Wi-Fi does have to be turned on and you have to be within range of one of those access points.