Figured out the intercom connections. Made the wire harness, and soldered the leads to the 25-pin connector provided with the intercom. The wire bundle was looking too large to fit into the shell. By the time I was near the end of soldering, the connector had got so hot that one pin was hot enough to melt and move out of position. I didn't have great confidence in the solder joints resulting from the last 3 or 4 wires joined either. Need to research a crimp-on alternative.
