Hi,
After I’ve generated and downloadet a map from garmin.openstreetmap.nl, I ran into “a minor” problem…
I’ve placed the file on a micro SD card:
X:\garmin\gmapsupp.img
When I’m placing the SD card in my eTrex Legend HCx, I get … nothing. Only the standard map is shown. I have asked Garmin’s support, but they seems to ignore my question (they answer in west, when I ask in east).
Please - could someone help me out here:
What did I miss, since I can’t get the new map work???
Regards
JeanJensen
Have you tried X:\Garmin\gmappsupp.img?
Only a small difference for us, but a big for Garmin 
HTH,
ajoessen
X:\garmin\gmapsupp.img should work, sometimes a microsd card fits not right in the slot, or the connections can be dirty, or it can be a defective card. Try to format the card or use another one.
I’ve tryed both - same (none) succes…
I’ve now ordered a brand new micr SD card… The one I have now, is formatted and totaly cleaned, and still nothing usefull.
I’ll get back when I recieve my new SD card.
BTW:
http://geo.jeanjensen.dk/wp-content/uploads/2012/01/legendHCx.swf
I didn’t see any reference to card type above:
Should be 4GB max.
See:
https://support.garmin.com/support/searchSupport/case.faces?caseId={9dec4ad0-954a-11dd-f60b-000000000000}
Also, you are probably better off getting the SLOWEST card you can find in that size.
You have to select the map, go to the map page on the etrex
press
select “setup map” press the press selcect “show OSM…” press if you have also installed an other map than press again "select the other map example “Hide City Navigator” and press the
Hide City Navigator means that this is the map you see on the screen of the etrex
Show City Navigator means that you don’t see this map on the screen of the etrex
If you see Hide City… and Hide OSM… than you will see the City Navigator map on the etrex.
Okay - this might be the problem… My SDcard is at 32 Gb 
The link is for the older generation Garmins with removable memory. The newer generation Garmins that take raster maps can use up to 32Gb, but they still have a limitation of 3000 tiles for vector maps and use the additional memory for Birdseye or Custom raster.
How do I know, how many tiles the map holds? A map for Denmark e.g., downloaded from http://garmin.openstreetmap.nl ?
This is much easier to do in MapSource than BaseCamp. In MapSource you select an are of maps you want to load. The tilese will be tinted pink, and outlined with yellow, and in the left window of the MapSource screen there is a maps tab that lists the maps and totals the number of tiles (maps). BaseCamp has a separate “MapInstall” app that runs after you’ve connected your GPSr to your computer. You need to right click on the GPSr icon to start it. MapInstall doesn’t list the maps however, so you need to count the yellow outlines by hand.
But 2025 is a LOT of tiles. Garmin’s City Navigator for the US and Canada contains only 142. I doubt that all of Europe has many more than that although road density can affect number of tiles.
When you select a country from the drop down list, it will list all of the selected tiles in a column on the left. For Denmark, its only 13 tiles. So it is nowhere near the limits anyway.
But a etrex Legend HCx as mentioned in post #1 is definitely an “older” Garmin.
Grretings,
ajoessen
The link lists the OP’s Etrex.