Here is a sketch of the original M242 wiring diagram. It was about a simple as it could be. These days we would be more likely to run a two wire system throughout. One, in-line fuse served the whole system. The interior cabins light were always “hot” (they had their own on / off switches), The three ways switch was off or with one pull the nav lights came on and the second pull ADDED the mast light (steaming light). The threeway switch was on the port side of the hull liner at the back end of the liner. The wiring was pretty much on the port side of the boat. It ran along the side deck right against the cabin side. The wiring harness was actually installed on the deck liner part (with tape) before the deck liner was bonded into the deck part. The battery was in a standard battery box with a lid and strap around the box to hold everything in place - you may find some strap anchors on the hull surface just aft of the hull liner. The mast came wired with a two wire lead from the mast light which came out of the mast at cabin top level. This was equipped with a plug which plugged into the power from the mast light wires which were in the deck liner near the mast hole.
