The local otis guru by me told me a couple years back that
on the 411 controllers you need to routine all the connections, especially on all the wires that have those crimp on ferrule ends, ever 250k runs or so. I had some 411's in a hospital that were worn out and had tons of intermittent mystery problems. I went through the whole thing and id say 65% of the terminals were able to take at least 3/4 more of a turn. Probably 5-10% of the wires with the ferrule ends took 1.25-1.5 more turns. After that 99% of the mystery problems went away.
