How can the internal GPS be bypassed in the Skymap IIIC?
The Skymap IIIC has a built-in GPS receiver. To use this unit with an external GPS source. use the following steps to disable the internal GPS receiver: 1. Press the SET UP key. 2. Press the INST & DIAGS key. 3. Press DATA IN/OUT key. 4. Use the Joystick to select ‘GPS Source’. When you try to toggle, you will get a message asking if you really want to do this. Select YES, and then it will let you toggle the GPS source.