The basic procedure is this: 1) Fomat the SD card FAT32. 3) Copy file from your nuvi into the \Garmin folder of the SD. You should now be running with the new maps on the SD card.4) Disconnect your nuvi and put the SD card in your computer's card reader. The SD card will be recognized as your nuvi 5) Proceed with the map update using Map Updater as normal. Look at Map Info to make sure the correct maps are enabled. (For those who remember, I have turned off all the IPS blocks in the router....) I did a screen capture of alandb's post and printed it out for the Manual I've Created...Note: Currently, the OTP authentication feature will cover any “Change Password” activities.We will soon be extending the OTP authentication feature to more functions in future to better protect your account."Text-to-Speech" technology clearly pronounces all street names over the built-in speaker to guide you to your destination without the need to take your eyes off the road or fumble with a map.A USB cable connects the unit to your PC for updating music and pictures, or charging the battery.
MAX232 is used to interface the circuit with PC for monitoring the data.I did save a link to the steps necessary to download a map to an SD card in a Nuvi 660, but it's a bit un-clear as to the steps.I believe it is not an "automatic" procedure as in newer units..... And since your nuvi 660 isn't among the auto-updatables, follow this from the above link: If your device is not listed above, please select the appropriate link below for steps on how to load maps to an SD card: Onetime Map Update: https://support.garmin.com/support/search Support/case.faces?The unit delivers reliable navigation with pre-loaded 2D or 3D maps for all 50 states and Canada, points of interest, Text-to-Speech voice guide, and automatically adjusts for day or night viewing.The touch-screen permits easy input for stored addresses, and lets you plan your route by entering an address, an intersection, a point of interest, or a city center as a destination, and detours around areas you wish to avoid.