* If you have purchased a map & have a disc, card or download - follow the retailerís directions.
* If you want to transfer maps, parts of maps or combined maps with MapSource or BaseCamp or HomePort, then read their very good help files.
* For those of you who have been given a map by a friend like the ones in some threads here, read on.
* If youíre not confident working with Computer directories, please get someone who is competent to help you so you donít turn your GPS into a paperweight.
The Maps for your Garmin GPS are .IMG files, when you download or have a file named gmapprom.img or gmapsupp.img you donít have to do anything to the file to transfer it to your GPS . Unless itís in a .zip or .rar file, if so unpack it first.
Thatís assuming you downloaded the unlocked file, if you have a locked file, unlock with fast image unlocker or go back & download the unlocked version.
There are different ways to update the map on your GPS, it depends on your Garmin model. Please read notes at the end no matter which method you use.
For The Current & Latest Garmin Series (1xxx/2xxx/37xx)
First you need to set up your computer. What you need to do before you replace City Nav or gmapprom.img with a newer unlocked map version is first turn off Garmin Agent if you have it installed on your PC, then in Windows Explorer under Tools/Folder Options/View, make sure that you have "Show Hidden Files & Folders" checked as well as removing the tick from beside "Hide protected operating system files" a couple of lines below. Then apply. You can reverse this setting to hide the files & folders on your PC when youíre finished by simply ticking ďDonít show Hidden Files & Folders"
Now youíre ready to start.
After connecting your Nuvi with USB cable to your PC it will boot into Data Transfer/USB/PC connect mode, this may take a few seconds to a minute then if auto play asks, select ďOpen folder to view Files,Ē you will be able to see your Nuvi, if not go to Computer, locate your GPS right click - select explore, now you should see a folder called .system. As well as a few others, .system is the one we want.
1: Make a backup copy of .system folder & any others you feel important (all of them) & save to your PC for just in case something goes wrong, eg; a power outage or PC crash - incomplete data transfer can cause problems that you may need a copy of your GPS files & folders to fix!!
2: Open the System folder on your Nuvi
3: Replace old gmapprom.img with new gmapprom.img by drag drop/copy paste (say yes to file overwrite/replace - you've saved a copy for justin) This process may take a while to complete.
4: Junction view files should be updated with every new City Nav map - make sure you have the right one then, open JCV Folder. Delete old JCV file - (you've saved a copy for justin)
If you canít find JCV folder, your model Nuvi probably does not support Junction view. If not skip steps 4 & 5.
5: Put new JCV file in JCV folder.
6: Now close windows explorer & eject USB drive (your Nuvi)
7: Remove USB cable
8: Let your Nuvi turn off or reboot.
Job done, your new map will load when you turn it back on.
You can also as an alternative 1: if there is enough free space, create a folder in the root of the Garmin Nuvi called Map then rename the new gmapprom.img to gmapsupp.img & put it in the Map folder.
Alternative 2: put the renamed file gmapsupp.img on a MicroSd card (formatted Fat32) in a folder named Garmin then insert in Nuvi, if it has a card slot, select or deselect the map in tools/settings/map/info.
Alternative 3: Most late model Nuviís support multiple maps with anyname.img on a MicroSd card or in the root of the device if they are in a folder called Map. All you need is enough free space.
City Navigator AU is around 180 MB & growing with each release, OZTopo2.1 is 1.3 GB, Garmin Topo Au NZ is 2.6 GB. (You will need a card for this until internal memory of new GPS gets bigger).
When you turn on the Nuvi you will need to go to tools/settings/map/info & turn on or off the map you need. New maps usually default to on. You can have all the maps running at the same time, however it may slow start up & search function if too many or too large.
For Older Garmin GPS
Maps will be inside a folder called Garmin, the gmapprom.img map is the original pre-installed map
To update this map you can:
1 - Replace the original map (gmapprom.img) with the one downloaded, you can rename the downloaded map to gmapprom.img if it is named something else like gmapsupp.img
2 Ė You can use the downloaded map named gmapsupp.img just copy to Garmin folder.
3 Ė Using an SD card
Format card to Fat32 if itís not already & create a Garmin folder. Copy the gmapsupp.img to the Garmin folder. You can use only one map on the SD card. See Notes.
Most late model handhelds also support multiple maps with anyname.img on a MicroSd, however the folder must be called Garmin.
Some also support this on the GPS internal memory if there is enough space.
If your adding Topo maps it is unlikely there is enough space internally for the whole map so you will be better off using Mapsource or BaseCamp map install to create maps for the region you want.
Older handhelds: You will need to put 1 map file named gmapsupp.img on an Sd card or a portion of the map/s in the internal memory, multiple maps are achievable see notes below.
Garmin GPS with Garmin Data Card: Should have a serial cable to connect to PC, will be very slow.
To speed things up.
Credit to precious for the following bit of info.
You need the Garmin data card reader/writer
You can get them on Ebay
* You can have 2 maps named gmapsupp.img one in the GPS and one on the SD card.
* You can make small maps for your GPS with limited memory by selecting only the map region tiles you need in Mapsource before transferring to your GPS. (Read MS help files)
* You can combine multiple maps in Mapsource & with Gmaptool to make one gmapsupp.img. So they can be selected on your GPS as separate maps. (Read their help files)
* Mapsource will make a folder called Garmin on your device or card & will overwrite any map named gmapsupp.img in that folder if one already exists. Backup, Backup before you start doing anything you donít understand.
* There is a 4GB size limit for .img files on your GPS & SD card due to Fat32 limitations. There is also a maximum tile limit for maps that varies from small to large depending on the individual GPS model, too many to list, Google it.
* JCV - junction view, 3D Building files, etc. are for devices with this capability. If you canít find them on your GPS then you canít just add them & make them work. Although if you do & it works please share.
* If you download a map & transfer to your GPS & it doesnít work, donít panic, download it again, sometimes they get corrupted in download, unpacking, or transferring.
* Some .rar files refuse to unpack; I have found that renaming the extension to .zip works, most of the time if the file is complete.