How To Pull Wire Without Pulling Your Hair Out

Running wire or cables below deck can be frustrating at best. But these simple tips, along with some patience, can make the job much easier.

Like the wiring and plumbing behind the walls of our homes, boats also have myriad wires, cables, and hoses hidden below deck, within gunwales, and through piping. These arteries connect a boat’s essential systems and are typically installed in the hull before the deck and other structures are assembled, providing easy access and routing options for builders.

At some point, however, most boaters will add aftermarket accessories or need to make repairs that require running new or replacement wires. Common additions to new boats include transducers, additional lighting, trolling motors, and audio equipment, among many others.

Most boats are built with chase tubes, usually made from PVC pipe, that run under the deck and between the stern and the helm, sometimes to the bow. The chase tube provides a protected highway for wires, control cables, hydraulic lines, and other rigging items, and is usually the best option for running new wire. An adequately sized chase tube can make pulling wire a simple task, but one that is already jam-packed, or makes sharp twists and turns, can make the job increasingly arduous. Occasionally, a boat might not have a chase tube at all, and a viable new route must be identified or created.

In either case, here are some proven tips and techniques that are guaranteed to make the job easier and less stressful.

>> Go fish. Many manufacturers or previous owners will leave a pull string or “messenger” for the next time someone needs to pull a wire. This is usually a piece of nylon or nonorganic cord that is at least twice the length of the run, with plenty of excess coiled on each side.

If not, you’ll likely need to go fishing. A “fish tape” is a flexible, semirigid “snake” that electricians use to pull wire in spaces inaccessible by hand. A fish tape can be pushed through the chase and to the destination, where the wire is attached to its end and pulled back through. Whenever possible, insert the fish tape into the most easily accessible side of the chase so you have the greatest possible range of motion to manipulate it. In a crowded chase, it can be difficult to get through, and it may take many attempts. Go slow and try multiple angles until you find the path of least resistance.

When running small wires, they can sometimes be attached to the leading end of a fish tape or push rod and pushed through. If the run is complex, often it’s easier to use a pull string to pull the wire. In this case, attach a sturdy pull string to the fish tape and push it through, then use the string to pull the wire back. Remember, always make the pull string long enough to retrieve for next time or pull a new string at the same time.

Fish tapes are available in various materials and sizes, but be sure to use one with no sharp edges that can damage existing wiring. Many fish tapes are made from steel ribbon and should be used very carefully. A great DIY alternative is the stainless steel inside of a control cable. Use wire cutters or a cut-off wheel to remove the connecting ends of the cable. With the ends removed, the steel inside will pull out of its protective jacket. You can then create a small loop on one end using pliers. Because these cables are round, they slide smoothly and won’t damage existing wires, but you may need to file the ends, as cutting the cable can leave a sharp tip.

>> Streamline connections. Most chase tubes will be tight inside, and anything you can do to make your wire’s journey snag-free will help. When connecting the wire to the fish tape or pull string, avoid cumbersome knots, and opt for twist-type connections. Don’t install termination connectors until the wire has been pulled. Make sure the connection is strong, as sometimes you need to apply significant force, and there is nothing more disheartening than having a break midway through the pull.

Use electrical tape liberally to cover the entire connection, smoothly extending wraps well above and below the main connection while avoiding building the tape up to the point that it could cause a snag. If the connection point isn’t naturally tapered and smooth or has a plug attached, use more electrical tape to build up a bullet shape that will naturally part its way through a sea of wires. If you need to run multiple wires, consider pulling them together in one pull. Do not twist them together, as it will be impossible to remove just one in the future.

>> Let it slide. Ease friction and pass obstructions in the chase more easily by using a wire lubricant. You can find specialized gels and aerosols designed for the task at most home-improvement stores. Silicone spray is a common choice on boats, and for those not wanting a gooey mess, body powder is also effective. Avoid soaps and petroleum-based products, which can degrade wire insulation over time.

>> Enlist a friend. Pulling heavier gauge cables can be more difficult because of their larger size, but they also offer the opportunity for a push-and-pull motion that can help work wires through corners and tight spots. If you reach a binding point and cannot pull any farther, have another person on the “pushing end” and gently work the wire back and forth. This technique often helps pass difficult locations within the run.

>> Get creative. Sometimes fish tapes are not ideal, as they have the tendency to wander if not in an enclosed conduit. For example, structures like T-tops with many pipe joints can make pushing a tape very tricky. In situations like this, there’s no right or wrong way to get the job done, as long as you get the wire where it is supposed to be. One clever trick when working with piping is to use suction. Put a shop vac at the hole you are trying to get the wire to, then feed yarn (sometimes with a cotton ball tied to it or piece of tape) in the entry point and suck it through. You can then use that yarn to attach to the wire or sturdier pull string and pull it through. It’s a simple trick that works remarkably well.

Another unconventional technique for routing through piping is to tie a steel washer to the pull string, then use a strong magnet from the outside to pull the washer along its intended path. Again, whatever method gets the wire where it is intended to go is a good one as long as it doesn’t abrade the wire or give problems with electrical runs.

>> Find a new route. If no chase tube exists where you need to go, or you simply cannot get another wire through it, it’s time to look for a new route. This can get tricky, and a diagram of the boat’s construction can be helpful. When planning a route, avoid moving mechanical parts, heat sources, fuel tanks, and sharp edges. A borescope can be useful if you can’t see where you’re going. Sometimes up through a gunwale between the hull side and liner can be an option, but it depends on your boat’s construction. In bigger boats, you may be able to go up and through a cabin structure. Again, take your time and be creative. Depending on the nature of the run, be sure that the wire is adequately anchored within the run to keep it from abrading on other structures or sharp fiberglass shards.

Pulling wire in a boat isn’t on the top of anyone’s list of fun weekend activities. But with the right techniques and a bit of persistence, you’ll be back on the water and pulling on the wheel instead before you know it.