If you have a 1982-83-84 car or truck never drive it with the wires on the side of the transmission unplugged/TCC Unlocked. This will overheat the transmission on a long trip. On a 1985 or later it is O K to have the wires unplugged, because of a design change made in late 1984.
Yes it's Ok to Lock manually. Don't do it at WOT tho'. This can/will smoke the TCC/TorqueConverterClutch.