27 Wiring
The 27 from the factory has the wiring leading up thru the mast step. It passes thru the mast compression post inside the cabin. It's virtually impossible to rerun these wires with the same method. If you need to re-rig the electrical, you'll need to re-run new wires from the electrical panel, thru the cabin, to the cabin ceiling at the base of the mast. Then get a "cable-clam". West Marine part # is #540740, 540732 or 540757, depending on the size you need to feed thru all the wires you want to go up the mast. Drill a hole to mount the cable clam thru the ceiling to the outside of the deck next to the mast, in front of the deck beam that passes laterally across the cabin top. Install the cableclam and lead the wires thru it. Drill a hole large enough to feed all the wires thru into the side of the mast just above the deck level. Now you'll need to drop the mast. Fish the wires thru the mast using an electrician's fish tape (a 50' one is available at Home Depot for about $15). It's a hassle getting the wires back to the outside of the mast at the spreader level for the decklight/steaming light, but just be patient and use your ingenuity. Be sure to use some sort of method to hold the wires away from the inside of the mast, otherwise they'll drive you nuts at night slapping the inside of the mast. I taped foam rubber around the wires every couple of feet. Also be sure to run a 3/16" dacron line thru the mast with the wires, and tape the wires to the line with electrical tape to take the pressure of gravity off the wires so they don't tend to pull off the connectors. OF COURSE, I'm assuming you don't have internal halyards. If that's the case, you'll need to rivet a PVC pipe up teh inside of the mast to act as conduit.Good luck. It's a lot of work, but you only need to do it once.PS, you'll probably also want to replace the mast step. They're available on the web from Catalina Direct.PPS As long as you have the mast down, drill a 3/8 hole at the base of the mast to allow any water that gets inside the mast to drain out. When I dropped my mast, it had about a quart of water inside!