The TZT has two connection modes for wireless.
1. Where you connect things (like your IPAD) to it. (Server)
2. Where it goes out to connect to the internet for weather. (Client)
You can NOT do both at the same time. For weather, you must go to MENU - GENERAL - WIRELESS LAN SETTINGS and setup the wireless mode to "CONNECT TO EXISTING LAN".
It will show you the WI-FI services that it sees. When you connect, it should provide a checkmark next to the wireless "server" that you are connected to. Once you have a good established network with a Wi-Fi network (that has access to the internet) you should be able to get your NavCenter weather, which provides a status bar showing as it downloads. (after you have started the download by picking update weather from Roto-Key) Once it finishes, you should turn on the weather items (with the rotokey) and see data.