How to make wireless stay connected?

[joe at actionline.com]

I have several thinkpads with linux mint connected via wireless and all
of them automatically connect when turned on and stay connected ...
except on the most recent linux mint 18 installed thinkpad.

Every time I close the lid it disconnects the wireless connection and I
have to re-enter the network password to get it started again.

What do I need to do to make it automatically connect and keep its
connection?

PS: I hate the KDE wallet nuisance and have it turned off.
Please don't make me have to use it to achieve what I need.