Question on Map upgrade loaded onto an SD Card....

I have never deleted my file on my sd card before updating the map. Didn't knw to. I don't have any problems with not deleting them.

@JanJ

There shouldn't be any need to rename map files if they are put there by Express or MapUpdater. How are you putting your map files onto your card?

I take care of updating maps on 3 units. All have the maps on the SD card, 1 I cloned there and the other 2 were put there by GE. I never had to delete any maps or rename them when updating.

I have never stored my maps on the SD Card. I do store my Waypoints and Routes as well as Red Light Camera, etc. on the card. No problems or issues so far.

I regularly have to clone the 855 on an SD card. All you need on it is the Garmindevice.xml file and a ASR folder. There is a good thread on cloning on POIfactory.

I have to delete all the existing map files on the SD card since the new ones have a different name and will NOT overwrite the old ones.

Then when all is downloaded I have to rename 3 files otherwise the update will not work.

romanviking, it is not a question of storing the new map files on the SD card, it is a necessity if your GPS does not have sufficient storage space ie my 855.

Older devices needed files to have specific names but with newer devices that is no longer the case.

Also, using the cloning method on newer devices, you don't need the ASR folder as GE will create it on the SD card.

OK...

I have 2 different SD cards for the 660... Each has /Garmin Directory, so it acts like a 660 to GE program....

With that, I took the 2nd of the 2 cards to Laptop with latest GE... Which saw the SD card as my registered Garmin 660....
I DID NOT PRE-REMOVE THE EXISTING MAPS FROM SD CARD.
And it told me a Map update was available...
So I let it update.... When Done... I examined the Garmin directory....

Unfortuneately, there were 2 sets of the three Garmin Map files.....

One set (The older ones) still remained, and they had the "supp" file names that I had renamed, after they were downloaded in 2017...

And a Second JUST DOWNLOADED set of 3 map update files.... BUT:

THEY WERE NOT RENAMED WITH THE "supp" filenames..... So they Will Not Work... as SD Card Files.... without renaming...

Now I know

@JanJ ... You are correct that older devices like the nuvi 3xx, 6xx and 8xx need to have the old map files deleted and the new files renamed when using cloning to update maps. Garmin Express does not support map update directly to a SD card on these old models, so cloning is your best method to update directly to SD, but requires the manual renaming.

On the 3xx and 6xx which have the 2 GB file size limit, another option is to use Express to install the map to computer, then use MapInstall to install a partial map to internal storage, and the remaining regions to SD. This method can give you the full NA map instead of just a partial map.

Correct me if I'm wrong, but if you do the MAPINSTALL route, don't you lose something? I think it is the same as the JCV file would let you see.

MapInstall only installs the map. So if your device has added features like junction view that will not be updated. For those devices you need to use the cloning method or Express/MapUpdater.

I was wondering if I left renamed files on SD card if GE Map Update would see these files and load new ones with same name...

Not the case, as I found out!!!

Also, after years of use, I've had first SD Card go bad...
Maps would not load... when in Garmin....

Only thing that I saw was file copies to this device began at normal speed, then progressively slowed down to a crawl...
Even tried a fresh format and got same results...

Switched to new SD card (32Gb-- all I had available)... and that worked....

So I've answered a couple of problems today!!! !

Yes, that is correct on newer devices that have special features like junction view, voice recognition, etc. But on JanJ's old nuvi 660 there are no feature files, so nothing is lost with MapInstall.