Originally Posted by mello mike
I searched the archives for this one specific problem but couldn't find anything on it. My main door lock works fine from the outside but I can't lock the door from the inside. Any ideas on what I should look for?
A 1972 trailer came with a KT lock.
You will have to remove the lock to check the back side operation.
There should be a problem with the "vertical locking shaft."
KT lock parts are available, but just like a new KT lock, not cheap.