Originally Posted by BigTJohn
Same thing as boats - try to use BOTH hands when tightening the sealing ring. For some reason, known only to engineers with whom the developers are friendly, using both hands will allow you to maintain alignment and keep the ring even when getting it started. Try it one day, you'll be surprised.
You are correct that if I use both hands, and lots of pressure, I can get a few threads to grab hold and secure the connection.. but not like the Marinco 15a connector grabs hold and threads in. I believe that the connector on my 30a cord is an aftermarket (non Marinco) type and just doesn't have the depth on the locking ring to do the job correctly. I am going to try to swap the locking rings and see what happens.. A new Marinco plug is an option or even a new cable all together and make the old one into a 30a extension by changing the questionable connector with an extension type.