Map installation on nüvi 2475LT leftovers

You shouldn't keep a .system folder on the card. Any files there should be copied to the same place in the .system folder on your device. Then delete the one on the card.

I have been searching for any means to get the unit to install to the SD card. The unit itself can see the card is installed and reports the size correctly. I came across another section where it was recommended to delete some files from the \GPX\Archive folder. I checked mine and found 20 files taking up 32.9 MB. The most recent file has a date of 27/12/2018. Would deleting those files help solve the problem?

No.  Exactly what though do you want to install to the sd card? 

I am still trying to get the nuvi 2475LT to install or update the North American maps onto the SD card seamlessly. It is tedious to have to go through the Clone procedure everytime an updated map is available. It seems this problem has been going on for years on various units. I would assume it is a fairly simple bug which could/should be addressed by Garmin.

Regrettably once you've installed the map rather than let Express do it then you will always be required to do it. Express quite reasonably won't replace maps you've installed yourself.

I can't recall why you started doing this, but what you could do is delete the map from your sd card, then run Express. It should detect you have no map installed and attempt to install it for you. Express generally works well and has not failed to update my maps except once when I failed to update Express.

I had to clone it because Garmin Express didn't update it. It was through your good offices which took me through the whole procedure. Today I changed to a blank SD card of 8 GB and it still didn't download the map to the card, reporting the same message about insufficient space on the unit. I will try it again with a newly formatted SD card to see if it is the same.

OK. I just formatted a 16 GB SD card and installed it. Garmin Express still did not download the map, reporting again that there was not enough space on the unit. Utilities recognises that the card is installed. I have the latest version of Express, 7.3.0.0.

Have you deleted all the previous maps? What options did Express give? Incidentally how much free space is on your nuvi? If there is hardly any that can cause issues.

I only deleted the map on the SD card. I did not delete anything on the nuvi. It reports 90% full, 783.84 MB Free. The European maps are still on the nuvi.