PVC Pipe in Mast
There is a pvc pipe pop riveted to the inside front of the mast in my '89 Vision 32 that holds the mast wiring. I am pretty sure the mast would have to come down to install a new wire thru this chase. You could always drop a new wire down the mast using a weight without going thru the pvc pipe, but risk it interfering with the halyards, or clanging at anchor. You would need to cut a small (maybe 2-3") round hole in the mast about a foot or so up from the bottom. Using a flashlight, you could look into the mast and hook the new wire with a coat hanger and pull it out at that point. A round hole at that location wouldn't weaken the mast, but you want to avoid square which could creat stress cracks. If you can wait until you pull the boat for bottom maintenance, most yards have a crane that could pull your mast, making this a much cleaner job. Good luck!
