Chris, transferring your waypoints to the new-to-you garmin is easy. You just put all your waypoints on an acceptable SD card in GPX format and insert the card into the Garmin. In Menu select "manage user data". Then depending on the model of your machine you will see "Merge Data" or "replace Data". If your machine is cleaned of the old owners data, click "Merge Data". That will put the data on the SD card into the 8412. If there is waypoints on the 8412 that you don't want on there, click, "Replace Data". That clears the machine of all previous data. and installs your new stuff. That will put a COPY of what's on the SD card on the 8412. The data will remain on the card also. At that point, get out of menu, turn off the 8412 and remove the SD card. When you fire the unit back up, you should see all your waypoints. Additionally, you do not need any satelite signal to do this, so it can be done at home or where-ever. If you get tangled up, you can watch this video.
Thanks so much HH and sorry that i did not mentioned that i solved the problem.
I figured it out to reset the machines so that i got rid of the old owners lock what created one part of the problem.
Second part was that i imported my data from my AC Card and then had all WP's triple, so i reseted again.
I had all of my waypoints also in the Garmin/Navionics Boating App so i could export them and import them in AC,
that did the trick.
One of the dumb things of the Garmin MFD's is that they don't show the name of the SD Cards inserted and that makes it too easy to read or worst, overwrite the wrong card. My SD Cards have a stored name, ActiveCaptain, Maps and the third one is for Updates i download with my Starlink broadband Internet what is much faster then thru G4 with my cellphone. Well, i could download the Updates also with Starlink on my Cellphone and then from the Cellphone to the MFD's, but that takes forever, so i prefer to use the SD Card to update all Garmin devices.
The Garmin MFD show only Slot 1 and Slot 2 for each device and in my case also Slot 3 and 4 of the external SD card reader.
If Garmin would implement that the MFD will show Slot
and Name/description of the SD Card would make life a bit easier.
However, transfer worked and i went fishing yesterday and it was awesome, the boat and fishing!
Chris