I have just read this informative article which explains almost all I need to know. Mechanical override: Lockup torque converters (at https://www.allpar.com/mopar/transmissions/lockup.html ) So let me start from the beginning. For ease of standardization, I have several Dodge pickups from the 1983 through 1986. We have a few from 1972 as well, but have just about retired those. I recently built a nice 1983 pickup with a Utiline bed for my son. I used the engine and transmission out of a 1987 Ramcharger I had picked up at a bargain. I bought it for the seats, console and glass; have wound up using the entire driveline. OK, backing up a little further, I bought my 1985 Ramcharger brand new, ordered it from the dealer. I have over 260,000 miles with amazing reliability. The transmission still shifts the way it did when brand new and the engine remains perfect. I wanted to build a similar reliable pickup for my son as he will off into the world far too soon. When connecting the wires on the tranny, I wondered what that one little connector was for? I didn't have a wire to connect to it. It certainly is not present on any of my other pickups and is not shown in the 85 Service Manual. After driving the vehicle for several months, it certainly does not lock up the Torque Converter. After reading several forums and looking at pictures, I now know this connector is to lock up the TC electrically rather than hydraulically. Here is my question. I could take the electric brains from the 87 Ramcharger and try to get it to work again to get the TC to lock up. Seems a bit too complex of a solution. Or, I could a connect a 12v lighted rocker switch. Cheap, but manually switching often is not a great solution. I really would like to make it automatic -- hydraulic like my flawless shifting 1985 Ramcharger. What would this take? Would it be just a change of the valve body? Buy a 1985 valve body and install it in the 1987 transmission? Thanks.