Boat owners, don’t leave shore without this!

I’ll cut  right to it: the last thing you want to do while you’re out at sea is diagnose wiring problems. But that’s when they happen, right? When a cable goes bad, it could be just a matter of having no satellite TV for the night. Or, it could be the cable that supplies internet to the whole ship. It could be a cable that’s keeping you safe by giving everyone cell coverage. No matter what, it’s something you’ll need to fix.

Let’s be honest… sometimes waiting isn’t an option. And that’s why you need to have the tools onboard to do the job. Like, for example, this coaxial cable mapper.

What does a coax mapper do?

A coaxial cable mapper has two functions. First of all it tells you if a cable is good. Second of all it helps you figure out which cable you’re actually looking at.

Testing the cable is relatively simple. If you’ve outfitted a boat with marine electronics you probably make your own coaxial cables. Chances are you have enough confidence in yourself to make them without testing. Personally I test every cable I make because it’s easy and quick. And, because, hey, nobody’s perfect. If you’re making a cable to go on a ship that’s going to be out at sea for a while, you want it to be well-made. You want to be sure.

The other part of a coax mapper is figuring out which cable you have. It’s very easy to get confused when you’re running cables from place to place. The simple way to test a cable is to use a multimeter, putting one terminal on each end. But, if it’s an installed cable, you can’t do that. A coax mapper has a special end that goes on one side of the cable so you can go to the other side. Connect four different cables up, use the tester, and it will tell you which of the four you are connected to. This will help you fix things and expand things with confidence.

Using a coax mapper

This short video goes through it pretty well:

Connect one of the colored ends to one side of the cable and connect the tester to the other side of the cable. Press the TEST button and you’ll see whether the cable is good, in what way it could be bad, and you’ll see which cable you’re testing. A light next to the correct color makes it clear.

A coax mapper will last months or years on a 9-volt battery. It’s smaller than a bar of soap and it will keep you out of trouble. One like this even has a hidden compartment for those four ends so you don’t have to worry about losing them.

Don’t leave shore without it

Whether you’re outfitting a new ship or just stocking up for a new journey, you’ll find all the marine accessories you need when you shop at Solid Signal. You’ll find a huge selection of marine electronics and waterproof accessories, plus all the tools you’ll need to complete most repairs no matter where you are. If you need help, call the experts at 877-312-4547 during East Coast business hours.


About the Author

Stuart Sweet
Stuart Sweet is the editor-in-chief of The Solid Signal Blog and a "master plumber" at Signal Group, LLC. He is the author of over 8,000 articles and longform tutorials including many posted here. Reach him by clicking on "Contact the Editor" at the bottom of this page.