Lionel TMCC - Back Coupler constantly activating

Help! I have a Lionel Chesapeake Super Freight Train wtih TMCC. It runs fine but constantly activating the coupler. I can’t keep anything attached. It clicks constantly. Any Ideas? I took off the top of the tender and looked at the wires but didn’t see any shorts. Not sure what to do. I am very new to model railroading and could use any help you can give.

Thanks

Marty

You’ll probably receive more replies on the sister forum dedicated to Lionel and similar trains.