First post here. I recently bought a used 2005 Honda Goldwing, which came with Garmin GPSMAP 376C GPS.

It's old and in need of map updates but, Not willing to spend money on an outdated, albeit a good GPS, when I already have 2 newer Nuvi's with 2015 maps installed.

Problem #1: This unit DON'T use SD card. Came with a proprietary Garmin data card, a maximum available 512Mb card(the ONLY good news).

Problem #2: Maps preloaded are from 2008, one general and one "deluxe" map sets. Took it San Diego few weeks ago and found out that Chula Vista city streets didn't exist(?) in 2008? Unit was COMPLETELY lost!

Problem #3: Being that it's "old technology", new NT maps will not load due to data card size limitation of 512Mb.

Problem #4: Most of the maps I got are in ".img" format, which I can copy and paste into the newer model's files but, can't on THIS model. It's internal system files are NOT accessible or even showing up on "My Computer" on my P.C like others do.

I managed, with help of MANY post searches on this site, to update the map to 2011.10 then to 2012.20 version, in segments for my areas of travel.

The ONLY reason I managed to do so, is because the map files I found is in the newer ".gmap" format which I unlocked using info from this site and are useable with Garmin mapsource.

Here lies my issues. I do have several newer maps, latest being 2015, in ".img" files, which can not be used, even if they are unlocked ".img" files, with mapsource...it will NOT recognize any of the map files.

So, I seek the wisdom of posters, here for guidance in "how to", so that I can create the latest 2015 map in several segments as I need them, to be installed in this unit.

Right now, I have the 2012 map installed, broken up into 4 segments; South Western US, North Western US, South Eastern US and North Eastern US. Each segment will fit on this 512Mb data card. Other segments will be loaded into my Notebook PC to take with me when we go on trips and may go out of that area which is loaded in the unit.

I always take a backup Nuvi285WT, just in case, mounted directly in front of me...Don't really trust this older unit 100% since the issues in San Diego where it didn't know where we were.

Thanks for any and all assistance provided.