The wifi on my GS4 keeps shutting off automatically when not connected to wifi system. So when I go to Google Maps, it's always asking me to turn it on. Is there a way I can set my wifi to be on constantly?
In your advanced WiFi settings there should be an option called "Kepp Wi-Fi on during sleep". This should be ON; otherwise your network will be turned off as soon as the screen shuts off (unless an app is actively using it).
Long-press on the WiFi button on your notification bar (or from the Settings, just go to WiFi). There, hit the menu button and you should see "Advanced" in there.