Garmin Colorado question

[JSinAZ]

Hi, great site here.  I'm new and am starting off with a problem.  I have a Garmin Colorado 400t, had the City Navigator and TOPO 2008 maps.  I wanted to replace the TOPO 2008 with the Arizona Topo maps here, I followed the tutorial, used Basecamp and Mapinstall to put the maps on SD card.  When I put the SD card in my Colorado and went to "choose map" the city navigator map was gone.   I didn't do anything else, just put the card in and turned it on.  What happened?  Is it retrievable.  Not the end of the world, I use this unit off road anyway but can't figure out what went wrong.

Thanks,
Jerry

[Boyd]

When you send a map to the GPS with either BaseCamp/Mapinstall or Mapsource/RoadTrip, it replaces any old map with the new one. The name of the map file that these programs create is always gmapsupp.img. Older Garmin models would only recognize a file with that name. This is unfortunate, because newer models like yours can use any name that includes the .img file extension.

If you didn't backup your City Navigator Map, then it's gone. How did you put the City Navigator map on your GPS in the first place? From a DVD? If so, you can replace it.

In the future, after sending a map to the GPS, look in the Garmin folder for the file named gmapsupp.img, then change the name to something else, such as ArizonaTopo.img. That will prevent it from being erased the next time you send a map. Repeat this procedure as needed and you can build a library of drag and drop files for your GPS.

BTW, you do NOT want to "replace" the 2008 topo maps on your Colorado 400t. They are treated differently from other map files, and Garmin's software will not erase them. They are found in the file named gmapprom.img and it will be almost 3GB. If you really decide you don't want them, be sure to back that file up on your computer, because it will be gone forever when you delete it otherwise.

[JSinAZ]

That is what I suspected, thanks.  I don't remember how the original was installed, I'll see if I have the DVD.  thanks very much.