Why can't I connect my GPSMAP 66 to a MacBook Pro via USB-C (with either a dongle or a Micro USB - USB-C cable)?

I have a GPSMAP 66 and a MacBook Pro with USB-C ports.

I cannot connect the GPSMAP 66 to the MacBook Pro, even when using a dongle to convert the USB-A to the USB-C, or even with a direct Micro USB to USB-C cable.

If I power on the device while it is connected, the GPSMAP 66 will boot, but then crash immediately. It never appears in the Finder.

It's a real problem for me. If I want to load routes I have made in BaseCamp, I need to upload them to the Garmin Explore website, then connect my GPSMAP 66 to my iPhone and sync it using GarminConnect. It seems ridiculous that I have to use my iPhone as the device through which I load routes.

0 Embraer over 4 years ago

I've had this happen a couple times with my New MacBook Pro (USB-C with a dongle) and my Garmin 66i. It seems like if I already have BaseCamp open when I plug in my 66i, BaseCamp doesn't recognize it being plugged in. I usually have to close and re-open BaseCamp to get it to see the 66i.

I have also encountered a problem where neither the MacBook Pro or BaseCamp see that the Garmin is plugged in. So, Sometimes I have to do both restart BaseCamp and re-plug in the 66i.

I also have this exact same problem with Garmin Express, it sometimes doesn't recognize the 66i..Usually the same solution works - opening and closing the app works (or unplugging/plugging the 66i into the MacBook Pro).

Sorry, this is kind of a late response to your problem. But, keep trying, it should work.....

0 5909892 over 2 years ago

Hi. I had exactly the same problem, tyring to connect my GPSMap66i to my Macbook Air, via a dongle, just as you describe above. Tried all the reboots and restarts suggested in the comment above with no luck. Also tried switching the unit to spanner mode as suggested in a Reddit post re same problem, that didn't work either. In the end what fixed it was a different USB cable! I have so many cables floating around so I don't know which is the one that came with the unit anymore, but in the end the one that worked was only 25cm long and quite thick, so probable a better quality cable. Anyway, its been two years since you posted your question so I hope you've had a solution well before know. Cheers.

0 2505143 over 1 year ago

Had the same issue - changed the USB to a better quality one and fixed immediately.

0 twolpert over 1 year ago

This is not a matter of "better quality" USB cable. It's the difference between "charge ONLY" and "charge + data". (There is no such thing as data only.)

Regardless of the connector type, there are wires that carry power for charging and wires which carry data. Charge only cables have ONLY the power wires. Charge plus data cables have both power and data wires.

This problem is not unique to the Mac, The problems occur on Windows as well. That said, Garmin devices play much nicer with Windows than they do with Macs. Issues tend to be much more confusing with the Mac.

My personal rule: If the cable CAME with a power source (for example, a power bank or solar charger), I IMMEDIATELY throw it away. It is almost certainly power only.

0 Rich67_ over 1 year ago in reply to twolpert

Absolutely correct. The Garmin cable connects immediately to UBS on my iMac, but generic USB charging cables only go to charge the 66i. Thanks for clarifying, because I was even at a loss a couple times while trying to use my 66i with Express.