Running P42 radar wire from mast to cockpit
Hi Art,
I also have a 1991 P42 (hull #65) and I did exactly what you are contemplating. I installed a 24" Furuno antenna on my mast and ran the wire from the mast to the cockpit instrument panel. I did it in 2000, so I apologize if my (ancient) memory has holes in it. But as nearly as I can remember, this is what I did.
1. Pick your antenna installation spot better than I did. I routinely climb my mast and stand atop the first set of spreaders for eyeball coral navigation. Had I installed my antenna above my own height above the first spreaders, it would be easier to climb the mast. Just one consideration.
2. I didn't run the wire inside the conduit that runs inside the mast. That made the exercise MUCH easier. Since it is a rather thick bundle of wires, and it is coated with a nice thick insulation, I was not concerned about that part of the installation. It has never been a problem.
3. I cut the end of the wire run that is the end farthest from the antenna, and utilized the antenna end connections as they were originally supplied. (You'd likely do this as well since you run the wires down the mast, not up the mast).
4. After drilling the hole in the mast (taking care to avoid the conduit, any loose wires inside the mast, and all halyards), I ran the radar wire into the hole and let gravity take it down the mast.
5. At the base of the mast the lowest B & R wires connect to the mast from the outer ends of the lower spreader tips. They connect to the mast in the holder that is not welded into the mast base, but is held in place only by the strain imposed by the shroud wire. Loosen and remove that shroud wire on one side (I removed the starboard side) at the base of the mast. There is a turnbuckle and it is easily accomplished. After the shroud is loosened, the holder piece can be turned sideways and removed from the mast base. A flashlight shined into the mast base through this hole gives you amazing visibility into the mast base. (Particularly when aided by an inspection mirror). You can easily find the radar wire inside the mast and grab it with a long screwdriver (or one of those nifty flexible retractable grab hooks that you buy for $10 at many auto parts stores).
6. From inside the cabin, unscrew the part of the cover that covers the top of the compression post and gives you access to the wires coming out of the mast. There is a short (maybe 4" to 6" long) piece of PVC pipe here that the masthead wires pass through. You will want to pass the radar wires through this pipe. Coat the wires with Vaseline and it will be an easier job.
7. Go back on deck and ensure that you have a drip loop in the radar wire. This ensures that the water that runs down the radar wires falls off before it goes into that little PVC pipe.
8. Go back into the cabin and ensure that the PVC pipe is siliconed into place so that errant water does not find its way into the cabin. Then once all wires are in place, fill the PVC pipe with silicone so that any water getting into the PVC pipe stays outside rather than running down your compression post.
9. You are now done with the mast base work, and you can replace your shroud.
10. Now comes the fun: running the wires. Just aft of the compression post cover you can see where the masthead wires run. As Terry noted, these wires run to the port side and then back to the nav station. You will get access along the way by removing the stereo speakers. You will want to take out your stereo amplifier (or whatever now occupies that space) for ease of dealing with the wires. This run takes patience; put aside some time for it. I'm not suggesting that you engage in my bad habits, but stopping for a beer/wine break at appropriate intervals helps. And don't forget the Vaseline coating. I found that the wires were so rigid that I pushed and pulled my way through it. I was ready to cut and re-splice one of the masthead wires for a messenger, but I found it unnecessary.
11. Make sure you leave enough slack line at the top of the compression post to cut all of the wires and install a junction box there. You will want to leave at least a foot or more of slack wires so that when you raise your mast in the future, you have slack to get the mast up (and down) without straining things. It will save you much aggravation when you are dropping the mast and can run the wire with the mast still 6" or 12" above the deck.
12. My installation is different than what you contemplate. I have a wire run to the nav area where I keep my radar scope most all of the time. Then I take the scope up to the cockpit when I need it up there for those delicate navigation purposes. So I have two wire runs. But in practice, both you and I are running wires to the cockpit instrument pod, so it's the same in the end. Again, as Terry noted, you run the wires down the forward corner of the nav station. You can get good access along the way by removing the "kickplate" cover that is next to the nav chair and up against the port side of the boat under the nav desk. Then down to that light (which you'll remove for access and helping things along). Then into the engine compartment, and running along the engine compartment to the bottom of the post that holds the instrument pod.
13. Your situation may be better than mine, but my instrument pod post is crammed with wires. I have a Twinscope sonar through there, and now the radar as well. Plenty of Vaseline. It'll get up there eventually. And then you're done. Enjoy another beer.
Please feel free to email me (paulcossman@hotmail.com) or contact me through this string if you have any other questions. I was able to do this without removing the mast and it was not difficult, just time consuming.
