All,
I found that my 1980 O'day wiring does not go down the starboard side of the boat as shown in the 79 O'day 25 wiring diagram. I found out the hard way that the forward running lights, bow (steaming) light, stern light and port compass light cables all run under the bridge deck, then turn to port at the bulkhead. They then go up to above the cabin liner where the stern light cable goes aft and the other three go forward.
In mounting my depth sounder I found there was a 1" cavity in the bulkhead. Today I drilled up from the bottom to run the wires hidden in the bulkhead instead of down the front of it. I drilled right into the wire harness.
In the photo you can see where I drilled. The light is the one over the galley and the wood is the bulkhead teak where the DC Panel is installed.
I was able to splice into the forward running lights cable (white cable in pic) and will tie into the stern light cable further aft. The two black wires are from the depth sounder. I will be covering them with some teak trim.
After I did that I ran a new cable forward to the mast and found path I can use to run a new forward running light cable to get rid of that splice.