How to turn OFF all location information Garmin Montana 700i in text messaging

It should not even be necessary to sync to make these changes.

All messages sent from an iR device include location information (assuming that the device had fix). If the message is sent with the Explore app, you have the option of suppressing the location in the message itself. Those check boxes control what the servers DO with the location information when they create the text messages that are actually sent. 

To be clear: Device generates message with recipient list, text, and location. All that goes to Garmin servers. If the recipient is an SMS number, the server optionally adds lat/lon as text, link to that online map with location, and name as signature. The result goes out to the SMS recipient via an SMS gateway and the recipient's cell network.

If you are SURE that the necessary checkboxes are unchecked, open a support ticket. 

I am super-new to this device and am struggling to make sense of it all. Thanks to your message I realized that I can use the Explore App on my phone to message, whereas I was working directly from the Montana. So, and yes, I see that on the app one can disable location. It works. I tested it. 

I have another question: If I put the Garmin Montana in expedition mode (to reduce screen time, etc. and to save the battery) can I use the Explore App on my phone to create and receive messages? That is, will the Montana in a reduced battery use state still relay my messages to the satellite? 

I am pretty sure that Expedition mode disables BT on the iR device. So that answer would be no.

BTW, I was not suggesting that using the app and disabling location on the message was a way to get around the problem with the check boxes on the account tab. If those really are broken, you should open a support ticket.

In the Expedition App on my phone, to the left of the line where you enter text, is a button: to deactivate or activate the function of showing map and location we have been talking about. I tested it and, yes, when I deactivate that button the message goes through but doe NOT include specific location. So that works!

But try as I might with the Explore.Garmin website on my computer (where the three boxes are located) I have not been able, by unselecting them, to stop the location and detailed may from showing up -- however: this pertains to messages sent directly from the Montana. 

My other issue:

Now what I want to do is to keep the Montana in 'expedition mode' and use the Explore App on my phone (I am a back-country cyclist) and see if I can easily and conveniently just use my phone on the handlebar. 

It may be that I could have used a far lesser model of Garmin to achieve what I need here! Oh well, live and learn!

will probably not work, expedition mode will switch off bluetooth and so the communication between the phone and the gps will stop

This is true of virtually every iR device. In expedition mode, BT on the device is disabled. The point of expedition mode is to disable all non-essential battery sucking features.

If you want BT, you will have to "fake" expedition mode by turning other stuff off manually. You can't get all the way there. In particular, you cannot disable the hourly automatic message check. But as long as you are sending logged points, this probably does not make much difference in power consumption. You can probably turn most everything else off manually (for example, screen, ANT+).

The link below shows approximate, expected battery life of Inreach devices depending on various factors.  Of course you’d want to test it out first before you take off on a trip.  You can kind of do a rough estimate on how many USB chargers you’d need to take on a trip.  I use USB battery chargers for my 66i.  I don’t even own a solar charger and have no idea if they would  work.  

The best advice I can give is to shut the thing off at night or whenever you don’t need it to save power   Sometimes it’s easier to turn it on and send a few messages and then turn it back off if you’re really trying to conserve battery.  If you have friends/family tracking you 24/7, that might not be a viable option though.

support.garmin.com/.../