Which files to delete from my Nuvi to make room?

If you want to be on the safe side, get an external SD card, create a directory called Garmin on it and put the new gmapsupp.img in this directory.

gmapprom.img is the pre-installed map, you probably don't want to delete it. If you decide otherwise, better make a backup before deleting it. gmapbmap.img is the base map containing only large roads and larger cities, not really suitable for routing. You could delete it but as it is only about 50 MB you wouldn't gain much space.

Another option would be to go to garmin.openstreetmap.nl and select only the tiles you are interested in and see if the generated map fits on your device.

You can get a 4GB SD card for less than the price of a first-run movie ticket. Just do that instead.

You can also delete some of the voice files to make room. These probably contain lots of different voices and languages that you never use, so may be taking up quite a bit of space. They should all be in the directory Garmin\Voice.

Of course, you should make a backup of these before deleting them, just in case it breaks something, or if you ever want to use those voices in the future.

When I tried to use Garmin Express to update my maps on my Garmin Nuvi 660, it said I didn’t have enough space so it would only download a partial map of my choice (Southern US and Mexico or select areas of the U.S.

Here’s what I did to get the latest maps.

1. Get a SD card for format it with FAT32. Garmin says it will only accept up to a 4GB card for the Garmin Nuvi 660, however I used an 8 GB card with no issues.
2. Create a folder named Garmin on the SD card.
3. Connect the Garmin device to the computer.
4. Copy the file named garmindevice.xml from the Garmin folder on the Nuvi to the Garmin folder on the SD drive.
5. Disconnect the Nuvi.
6. Launch Garmin Express. The SD card will now be recognized as the Garmin device.
7. Download the map(s) you want. I downloaded the lower 49 states.
8. After the download is complete, you will have 3 maps files in the Garmin folder of the SD card. They will be named gmapprom.img, gmaporom.unl and gmapprom.gma.
9. Delete the garmindevice.xml file from the Garmin folder on the SD drive so the SD drive will no longer be recognized as the Garmin device.
10. Plus in the Garmin Nuvi device. It will now be recognized as the Garmin device.
11. Delete the gmapprom.img, gmaporom.unl and gmapprom.gma files from the Garmin folder on the Nuvi. You have to delete them first because for some reason, you can’t just overwrite them. You’ll get the message that there’s no enough space.
12. Copy the three files from the Garmin folder on the SD card to the Garmin folder on the Nuvi.
13. Reboot the Nuvi. The new maps will now be loaded.

I then deleted the files from the SD card and used it to load almost 3,000 MP3 files to take with me in the SD slot in the Nuvi.

I was able to use this for my Nuvi 500. I only had to place the SD card in a card reader instead of the NUVI 500. The rest was completely correct. I did have to delete some unused language and help files plus the gmapprom plus the gmapprom1 files in order to have enough room. I had been working on this for some time without success- thanks!