How to Disable GPS on an iPhone
When playing videos, listening to music, or viewing pictures on your iPhone, having the GPS feature on can quickly drain your battery power. Fortunately, you can easily disable GPS functionality to improve your battery life.
Press the "Home" button on your iPhone. If your device is locked, unlock it by sliding the arrow icon.
Locate the "Settings" icon on your home screen. If you have rearranged your home screens, it may be on one of the other home screens. Slide your finger across the screen to access them.
Touch the "Settings" icon to access the settings menu.
Scroll down and find the option titled "General." Touch it to access the settings.
Locate the entry titled "Location Services."
Turn the GPS functionality off by touching the blue "ON" button. It will slide to "OFF" to indicate it has turned GPS off.