Rated 3 out of 5 stars

by Rob-007 on July 3, 2015 ·

Sadly this is history, but gContactSync works well.
gContactSync is being kept up to date and uses the now required OAuth2 - a more secure method of authentication that does not require application-specific passwords for accounts using 2-step authentication.

(Below TB means Thunderbird).

If you have this old Google Contacts installed, then 1st Uninstall it (via TB Tools menu/Add-ons and then select the old Google Contacts add-on and click Remove). Then open the TB Address book and rename the old Google address book to "old-something" or better yet, just delete it.

Then download and save the gContactSync xpi file from https://addons.mozilla.org/en-US/thunderbird/addon/gcontactsync/?src=search

[Note, if you block cookies in Firefox, then read the following link (If you do not understand what this means, then skip this step as the normal default Firefox settings work fine).see http://www.pirules.org/addons/gcontactsync/faq.php#cookies ]

Now install gContactsync as follows...

In TB, get to the Tools menu (Don't see it? try Alt-T) Open Add-ons from the Tools menu.
Near the top right of the screen, find the Options button (which is the gear shaped icon next to the "search all add-ons" field).
Click this Options (gear shaped) button and select "Install Add-on From File..." and locate the just downloaded gcontactSync add-on xpi file and select it. etc.
Let it install.
Restart TB.
It will ask how to set up - pick your Google email address from the drop down list (if not there then enter it). Take the default and create an address book named the same as your gmail address. This should be a new address book - if it is not, then change the name so it is new.

I told it to sync all groups and contacts, and told it to sink one way only - from Google to here. But the other options should work find. (I have seen suggestions to only sync the My Contacts group and not the group lists, but I find the group lists convenient.)

Now open TB's Address book - it may ask to login to Google. Do it. Give the complete Google email address. (It does not save the password).

It will now quickly set up a new TB address book for your Google contacts and sync it. You are all ready to go.
DONE!