Garmin GPSMAP 743XSV and Airmar B150M in 2023 Cobalt CS23

[zip465]

Thanks to this thread: viewtopic.php?t=5060

Decided to jump in with both feet, I mean how hard could it be... Here's the steps we (wife and I) went though to add the Garmin GPSMAP 743XSV and the Airmar B150M in a 2023 Cobalt CS23. This is def not a perfect path but without any sort of directions or wiring diagrams there was some trial and surprisingly very few errors.

1. Contacted Cobalt for assistance - they sell a kit to make the conversion, new dash panel and the Garmin unit. However zero instructions included, and zero meaningful support from Cobalt on the installation process. Local Cobalt dealer service center was of zero use other than ordering in the parts. So DIY it is...
2. Getting boat data to the Garmin unit. The Volvo Easy Connect device made that just as stated easy - I had to purchase this item. Found the Easy Connect interface on the engine plugged in the unit and connected via bluetooth - so far so good. BTW kudos to Volvo on documentation and support - nothing short of amazing. Now on to the NMEA 2000 interface but first needed to get up to speed on NMEA 2000, lots of reading, but found several youtube videos to be more useful - just Google NMEA 2000...
3. Now to find a suitable power source, a multimeter is your friend... located a 2 pin 25a connector that was on the accessory circuit. Wired up the Garmin and NMEA 2000 power cables with a single female DT connector. Power supply solved.
4. Built out the NMEA 2000 network with the Garmin NMEA 2000 starter kit and the directions garnered from the various youtube videos - it works! Really quite easy.
5. Lets test things out before getting too far down the rabbit hole. Hooked up the Garmin and NMEA 2000 power cables to power, NMEA 2000 cable to the Garmin, transducer cable to the Garmin, and the stock gages that will remain once the installation is complete. Boom it all works!
6. Removing the old transducer for the new Airmar B150M, this is where things went south... Trying to locate or better yet get access to the end connector on the stock transducer was next to impossible - took the caveman approach and just cut the cable, but did seal off the end of the remaining cable to prevent corrosion. Now I had to remove the old transducer, took a bit of doing thanks to the sealant the factory used.
7. Installed the new Airmar B150M and routed the cable up to the cockpit area. I used the 3M marine sealant/adhesive for the thru hull installation - warning this stuff takes 7 days to cure so be aware of that if you're following along here... There are quicker cure adhesives out there.
8. Next was routing cables, securing them, putting the dash together, final securing of cables, testing, and final closeouts of removed panels and such.

All in all I'd say this is an easy to moderate job to do, would have been easier with a wiring diagram for the boat (Cobalt refused to supply one and dealer service center has no access to them either...so they say...). The supplied new dash insert cutout for the Garmin is a bit oversize on the width, but workable. I may scan the old dash, make a new one and place the Garmin on the left hand side vs. in the center where it's a bit obstructed by the steering wheel but that's a later project.

Final result

IMG_4172.JPEG

[jhnmdahl]

Nice work, and thanks for the play-by-play! Many of these projects are pretty doable once you've seen someone else go through the steps - hopefully your post inspires the next DIY!