Chosen Solution
Why won’t the WiFi services not showing but Bluetooth is working? When I go to System Preferences -> Network, and WiFi it does not show up as an available network? And I’m unable to run the online diagnostics.
There are a few things that could be messing you up. The first is making sure the AirPort board is properly installed. Sometimes reseating the board can solve things. Follow this guide MacBook Pro 13" Retina Display Early 2015 AirPort Board Replacement Also make sure you don’t have any corrosion on the AirPort or logic board, a liquid spill could have done you in. And lastly, you may need to replace the AirPort board.