The old light on our compass was no longer working, and needed to be replaced. The original light was a red LED to help preserve night vision. Recent studies have shown that the red color itself does not really do much to help. It is more about the intensity, and most newer systems are moving to green LEDs. With this in mind, I bought the low-level, green replacement from Ritchie.
This was about the same time that we were converting our masthead light to a tri-color, which introduced some wiring changes. The result was that we had one switch for sailing and one for steaming, but you would only use one or the other, not both.
Since we wanted the compass light to be on if either sailing or steaming was on, I added two diodes, one connected to each switch. That way if either one was on, the compass light would get power. The compass LEDs draw very little power, so I was able to use fairly small diodes.
