Hello everyone my first post, so please be gentle...

A couple of weeks ago i have acquired a Garmin Nuvi 300 (it came in a joblot of electronics i bought) i don't know the history, so charged it up and it does work flawlessly.

It runs City navigator V8 with uk and ireland maps. I tried to upgrade the maps to latest 2013 western europe maps to no avail.
If i bring the maps through base camp it tells me i need to unlock them online. i tried to run mapsource and extract the gmap.img put on a 4Gb memory card and the unit does not see it... I am banging my head against the wall!

Can anyone help me upgrade to the latest maps? any help will be appreciated!

phonesurgeon wrote:Hello everyone my first post, so please be gentle...

A couple of weeks ago i have acquired a Garmin Nuvi 300 (it came in a joblot of electronics i bought) i don't know the history, so charged it up and it does work flawlessly.

It runs City navigator V8 with uk and ireland maps. I tried to upgrade the maps to latest 2013 western europe maps to no avail.
If i bring the maps through base camp it tells me i need to unlock them online. i tried to run mapsource and extract the gmap.img put on a 4Gb memory card and the unit does not see it... I am banging my head against the wall!

Can anyone help me upgrade to the latest maps? any help will be appreciated!

Nuvi 300's can not read maps files ".img" files larger than 2gig.

If your using Mapsource, build mapsets of your choosing the are less than 2 gig and put them in a garmin folder of either the GPS or SD. The western Europe was probably to large for the 300. A smaller UNLOCKED map should work of named correctly and placed in the correct folder.

In the Nuvi 300, the following paths and map names are acceptable (assuming there sufficient memory space):
GPS:/Garmin/gmapprom.img <<<< these are considered the default maps
GPS:/Garmin/gmapsupp.img <<<< considered a "supplemental map"
The above 2 names are interchangeable

On SD (Formatted as Fat or Fat32 is acceptable)
SD:/Garmin/gmapsupp.img <<<< considered a "supplemental map"

You can also download smaller maps by country from links on this site. Download those listed as UNLOCKED "IMG". Those are ready to copy-n-go to any GPS or SD and no unlocling is required.

If you create a map using mapsource and the GPS says it's LOCKED, you will need to unlock it. Download the tool named GImgUnlock.exe To unlock an IMG file, drag the IMF file onto the GImgUnlock tool icon and the IMD will be unlocked (Modified) and will then work.

Thank you that explains a lot now.

I managed to add 1 other map, i need to add another 7 maps...
So in theory going with what you said... SD:/Garmin/gmapsupp.img is the one i have added, and continuing with that theory SD:/Garmin/gmapsupp2.img, gmapsupp3.img... and so on and so forth?

No, for your device this is not possible. You can use only one gmapsupp.img and one gmapprom.img in internal memory and an additional gmapsupp.img on SD.
Read also >>>here and >>>here.