Repair & maintenance guides

How to Care for Boat Solar Panels, Connectors and the Charge Controller

A boat solar setup is quiet and almost maintenance-free, but salt, shade, loose connectors and a wrong battery setting quietly cut its output or hurt the batteries. Learn the cleaning, inspection and controller checks to do each season, and how to leave the system for winter.

How to Choose, Install and Maintain an Onboard Battery Charger

Pick the right marine charger for your batteries (how many banks, how many amps, flooded, AGM or lithium), mount and fuse it safely, set the charge profile, and use it to keep batteries healthy all season and through the winter. The AC (shore power) side is a job for a marine electrician.

How to Find and Fix Corroded Electrical Connections on a Boat

Track down the green crust and loose terminals behind flickering lights, dead gauges and slow cranking with a simple voltage-drop test, then remake the connection the marine way: tinned wire, a proper crimp, adhesive-lined heat shrink and a protective coating.

How to Find and Fix LED Lights That Interfere With Your VHF and AIS

Some LED bulbs and fixtures put out radio noise that quietly drowns weak VHF calls, DSC alerts and AIS targets. Run the Coast Guard's squelch test, track down the noisy light with a handheld radio, and fix it with distance, filtering or a quieter fixture.

How to Place and Adjust a Side-Imaging and Down-Imaging Transducer

Get a clear, even picture on both sides of your side-imaging sonar by putting the transducer in clean water, at the right height, level, and where nothing blocks its beams. Then test at trolling speed and fine-tune in small steps.

How to Replace Boat Battery Cables the Right Way

Swap corroded, cracked or undersized battery cables for tinned marine cable sized from a chart for its real length and load, with crimped lugs, adhesive heat shrink, terminal boots, solid support and a fuse close to the battery.

How to Replace Marine Speakers (Including Tower Speakers)

Pick replacement speakers that fit the cutout, match your stereo or amplifier's power and impedance, survive sun and spray, and don't throw off your compass. Then wire them with the right polarity and seal them so water can't reach the back.

How to Run New Wires Through a Boat (Chase Tubes, Pull Lines and Deck Penetrations)

Get a new transducer cable, light or power wire from the stern to the helm or up through the deck without a fight: use the chase tube and a fish tape or pull string, protect the wire from chafe and heat, support it every 18 inches, seal every penetration and label both ends.

How to Size a House Battery Bank: Load List, Usable Capacity and Charging

Work out how many amp-hours your boat really uses in a day, how much of a battery's rated capacity you can actually use with lead-acid, AGM or lithium, how much reserve to add, and how your charging sources change the answer, so you buy the right house bank the first time.

How to Test and Fix Your Boat's Navigation Lights

Learn which navigation lights your boat must show and when, then test them and fix the usual culprits such as corroded sockets, loose pole-light plugs and blown bulbs. Working lights are legally required at night and in poor visibility and are how other boats see which way you are heading.

How to Troubleshoot Dash Gauges, a Dead Tachometer or a Wrong Fuel Gauge

Work through dead or wrong dash gauges from the cheapest check to the most involved: fuses and breakers, power and ground, the gauge-versus-sender test, the tachometer's pulse setting and the extra checks for digital network gauges. Most gauge problems turn out to be a bad connection, not a bad gauge.

How to Upgrade Your Boat's Lighting to LED (and Keep Your Nav Lights Legal)

Switch cabin, cockpit and courtesy lights to LED to cut battery drain and bulb changes, choose navigation lights that are actually USCG-certified (not just LED bulbs), check voltage range and dimmers, seal every connection, and run the Coast Guard's simple VHF test to make sure the new lights aren't deafening your radio or AIS.

How to Use a 1-2-Both Battery Switch and Run Two Batteries

Learn what the 1, 2, Both and Off positions really do, a simple routine that keeps one battery ready to start the engine, how to check that both batteries are charging, and when an automatic charging relay makes life easier. Rewiring high-current cables is a job for a marine electrician.

How to Wire a 12, 24 or 36-Volt Trolling Motor and Charge Its Batteries

Set up the battery bank for your electric trolling motor the right way: matched deep-cycle batteries in series or parallel, a circuit breaker sized from the motor maker's chart, a proper plug, and a multi-bank charger that keeps every battery healthy. High-current wiring that runs long distances or ties into other systems is a job for a marine electrician.

How to Wire a Bilge Pump Correctly (Automatic Float, Panel Switch and Fuse)

Wire your bilge pump so the automatic float works even with the battery switch off, the helm switch gives you a manual override, and every circuit has the right fuse, wire size and connections kept above the bilge water. A pump that is wired wrong can leave the boat unprotected exactly when nobody is aboard.

How to Wire a Marine Stereo, Speakers and Amplifier Safely

Install or fix a boat stereo the way that keeps it working and keeps your battery alive: marine-rated gear, a fused feed from the panel, a solid ground, a plan for the always-on memory wire, UV-proof speakers, and an amplifier fused right at the battery. Plus how to stop the stereo from messing with your VHF and compass.

Installing a DC-to-DC Charger: Charging a Lithium or Second Battery Bank from Your Engine

A DC-to-DC charger lets the engine's alternator refill a lithium (or separate) house bank with the right charge profile while protecting the starting battery and the alternator. Learn why you need one, where it can and can't be mounted, how the fusing and cable sizing work, and which settings matter, so you can plan the job or check a technician's work.

Internet Near Shore: Cellular Routers, Signal Boosters and Marina Wi-Fi Extenders

For boats that stay within sight of land, a cellular router, a legal signal booster or a marina Wi-Fi extender can be a cheaper alternative to satellite. Learn which one fits how you boat, why antenna placement and cable length matter, the FCC rules for boosters, how much power they use and how to test that it actually works.

Is My Engine Charging the Battery? Test the Charging System With a Multimeter

A step-by-step way to find out whether your outboard's stator and rectifier/regulator or your inboard's alternator is really charging the battery, what the voltage readings usually mean, and when the problem is just a dirty connection. Exact test specs come from your engine's service manual.

Isolation Transformer vs. Galvanic Isolator: Which Does Your Boat Need?

Understand how a galvanic isolator and an isolation transformer each protect a boat on shore power, when the heavier, pricier transformer is worth it (stray-current marinas, aluminum boats, liveaboards), and what to ask the ABYC-certified electrician who installs it.

Keeping Chartplotter Charts and Software Current (Garmin, Raymarine, Simrad, Lowrance, Navionics, NOAA)

Old charts can show buoys that moved and shoals that grew. Learn how chart subscriptions and updates work across the big brands, where NOAA's free charts fit in, how to handle SD cards safely, how to back up your waypoints and routes before anything goes wrong, and a simple yearly routine.

Low-Voltage Disconnects: Keep the Stereo and Fridge from Killing Your Battery

A low-voltage disconnect (LVD) automatically cuts non-essential loads like the stereo, fridge and cabin lights before they drain the battery you need to start the engine. Learn how these devices work, which loads belong behind one and which never do, how to pick the cut-off point for lead-acid or lithium, and how to install one safely.

Make Your Own Boat Wiring Diagram

Trace your boat's 12-volt circuits one wire at a time, label them so the labels last, and draw a simple diagram you keep aboard. It takes a few weekends, but it turns every future electrical problem or upgrade into a faster, cheaper job.

Marine Battery Care: Test, Charge and Store for Winter

Check your boat battery's health, charge it the right way for its type (flooded, AGM or lithium), and store it so it is ready in spring. Most "boat won't start" calls start with a neglected battery.