If I found a garmin nuvi gps it got a locked on it
Most GPS navigation devices from Garmin has a reset function which allows user to access a Maintenance Mode screen with system information, diagnostic details or perform the reset function to restore Garmin Nuvi or other series unit to its original default factory settings.
Depending on which model of Garmin GPS unit you're using, the following routine can reset the Garmin device to original factory loaded settings, or bring up the Maintenance Mode with access to System Information and View Diagnostics screen, where users can see various logs, and of course, clear all user data (reset to factory defaults) or clear Waypoints.
In order to reset Garmin device or enter into maintenance mode, perform one of the following procedures:
Power off Garmin unit. Press on continuously the upper top left corner of screen and then power on the unit by pressing once on the Power button. You should be prompted to clear all user data, or asked if do you really want to start up in maintenance mode. Press "Yes" to reset (warning: all data will be erased and lost, so backup before proceeding) or enter maintenance mode.
Hack above works on Garmin Nuvi 660, 680 series.
Turn off Garmin device. Press down on bottom right corner of the touchscreen, and then power on the GPS unit. You should be prompted whether do you really want to erase all user data, or asked if do you really want to start up in maintenance mode. Press "Yes" to reset (warning: all data will be erased and lost, so backup before proceeding) or enter maintenance mode.
Trick above works on Garmin nuvi 200, 250, 360 750, 760 series unit. In fact, there is a video demo by user of Garmin Nuvi 360 on how to perform the hidden reset function.
Hope helps. (remember to rate and comment this answer).