Repair & maintenance guides

12-Volt Boat Wiring Basics: Circuits, Color Codes, Fuses and Wire Size

Learn how your boat's 12-volt system is laid out, what the ABYC wire colors mean, how fuses and breakers protect the wiring, why voltage drop and tinned wire matter, and how to read a wiring diagram, so you can troubleshoot smarter and know which jobs belong to a marine electrician.

Adding USB and 12V Outlets to Your Boat: Fusing, Wire Size and Placement

Phones, tablets and handheld radios need charging on every trip. Learn how to add a dedicated USB or 12-volt outlet the right way: choosing a quality marine socket, picking the wire size and fuse, deciding between a panel circuit and a direct battery feed, sealing the hole, and checking that the charger doesn't put noise on your VHF.

AIS on Your Boat: Receiver vs. Class B, MMSI Programming, Antennas and Checking You're Seen

Choose between a receive-only AIS and a Class B transponder, get the MMSI programmed the legal way, sort out the GPS and VHF antenna (or splitter), confirm other boats and the Coast Guard actually see you, and understand silent mode and AIS man-overboard beacons.

Autopilot Care: Calibration, Drive Maintenance and Common Faults

Keep your autopilot steering straight and safe, whether it is a tiller pilot, a below-deck linear drive or a hydraulic pump on a center console. Check the drive and rudder feedback, fix voltage drop, calibrate the compass, run a proper sea trial, and work out what common alarms and wandering courses really mean.

Battery Goes Dead While the Boat Sits - How to Find a Parasitic Drain

If your boat battery is flat every time you come back, something may be quietly drawing power while you are away. Learn how to tell a bad battery from a drain, find the circuit with a multimeter and the fuse panel, and fix the usual culprits without disabling your bilge pump.

Battery Isolators Compared: Diode, ACR, Combiner and DC-DC Charger

Learn what the box between your engine and your batteries actually does, why an old diode isolator can leave batteries never quite full, and which charging setup suits an outboard, an inboard or a lithium house bank, plus a simple meter check of the one you have.

Battery Monitors with a Shunt: Installing, Setting Up and Reading State of Charge

A voltmeter can't tell you how full your house battery really is. Learn how a shunt-based battery monitor counts every amp going in and out, where the shunt goes on the negative side, which settings to change for lead-acid or lithium, and how to read the percentage without being fooled.

Boat Bonding System Explained: How to Inspect Bonding Wires, Through-Hulls and Anodes

Understand what the green bonding wires on your boat do, how they tie through-hulls, running gear, tanks and engines to your anodes and DC negative, how to inspect and test the connections yourself, and which corrosion warning signs mean it's time for an ABYC-certified technician.

Boat Ignition Key Switch: Diagnosing No-Crank and Intermittent Problems and Replacing It Right

A worn or corroded key switch can leave you with no crank, an engine that cuts out over bumps, or one that won't shut off. Learn how to rule out the battery, neutral switch and kill-switch lanyard first, test the switch with a meter, and replace it with the engine maker's switch wired exactly like the original.

Boat Inverters and Inverter/Chargers: Sizing, Safe Use and What a Pro Must Install

An inverter turns battery power into 120-volt household current, which makes it as dangerous as shore power and a serious fire risk if it is fused or wired wrong. Learn how to size one realistically, what a safe installation looks like, the owner checks to do, and the mistakes (like backfeeding) that hurt people.

Boat Spotlights and Searchlights: Care, Wiring Checks and Using Them Without Blinding Anyone

A good spotlight helps you find markers, moorings and debris at night and signal for help, but only if it works and you use it carefully. Learn how to care for remote-control searchlights and handheld spotlights, clean lenses, check fuses and wiring, and use the beam in short sweeps that never blind other boaters.

Converting a Pull-Start Outboard to Electric Start: What It Takes

Find out whether your pull-start outboard can take a factory electric start kit, what parts the job really needs (starter, charging coil, rectifier, battery, harness, key or button, neutral safety), and when a dealer install or a newer motor makes more sense.

ELCI Retrofit: Adding Whole-Boat Shock Protection to an Older Boat

What an ELCI (equipment leakage circuit interrupter) is, why ABYC now requires one on new boats with shore power, what a retrofit involves and costs, and what to do when one trips. You plan, test and troubleshoot; an ABYC-certified marine electrician does the wiring.

Electric Linear Actuators on Boats: Kicker Lifts, Towers, Hatches, Tables and Seats

Electric actuators raise kicker brackets, fold wake towers, lift engine hatches and move tables and helm seats. Learn how they work, why water and side load kill them, how to fuse and test one directly on 12 volts, and how to replace one safely.

Electronics That Reset or Shut Off When You Start the Engine: Finding and Fixing Voltage Sag

If your chartplotter, fishfinder, VHF or stereo blinks off or reboots when you crank the engine or switch on a big load, the cause is almost always low voltage reaching the device. This guide walks from the cheapest checks (battery, connections, grounds) to the real fixes: a dedicated electronics feed, start isolation between batteries, and voltage-stabilizing converters.

Engine Clicks but Won't Crank - Testing the Battery, Cables, Neutral Switch, Solenoid and Starter

A click (or nothing) when you turn the key is usually a power delivery problem, not a dead engine. Work from the battery and cables through the neutral switch, start relay and solenoid to the starter motor using simple voltage-drop tests, and learn how to jump-start safely when gasoline vapor may be around.

Engine Hour Meters: Why Hours Matter, How to Verify Them and How to Replace a Meter Honestly

Engine hours set your service schedule and a big part of your boat's resale value. Learn the difference between analog meters and engine-computer hours, how to verify the real hours on a used boat, and how to replace a dead or broken meter while keeping an honest record of the old hours.

Fish Finder and Depth Sounder Transducers: Mounting, Fixing Bad Readings and Cleaning

Where and how to mount a transom-mount transducer so it reads cleanly at speed, how to track down lost bottom readings and noisy screens, how to clean and paint a transducer without ruining it, and why thru-hull transducers are a haul-out job for a pro.

Fish Finder Settings: How to Tune Your Sonar for a Clearer Picture

Get more out of your fish finder by setting frequency, gain (sensitivity), range, contrast, color palette and noise filters on purpose instead of leaving everything on auto, plus how to set the depth offset and track down interference from other electronics.

Fuel Gauge Reads Wrong or Empty? How to Test the Gauge, Sender and Wiring

Find out why your boat's fuel gauge reads empty, full, backward or jumps around, working from the free checks at the dash to testing the tank sender and replacing it safely. Most problems are a stuck float, a bad ground or a sender that doesn't match the gauge.

Fuse Keeps Blowing? How to Troubleshoot a Boat Fuse Block or Breaker Panel

Work through a blown fuse or tripping breaker the safe way: confirm it, tell a short from an overload, isolate the device or wire at fault, replace a worn breaker or panel switch with the same rating, and label every circuit, without ever fitting a bigger fuse.

Galvanic Isolator: Why Shore-Powered Boats Need One and How to Tell If It's Working

A galvanic isolator (or an isolation transformer on bigger boats) keeps stray DC current from the marina's ground wire from eating your anodes, drive and running gear, without cutting the safety ground. Learn what it does, the owner-level checks you can do, what failure looks like, and why the actual meter test is usually a job for a marine electrician.

Holding Tank Level Monitors: Fix, Calibrate or Upgrade Your Tank Gauge

Find out why your holding tank gauge reads wrong, clean or calibrate the sensor, and choose a better internal or external monitor so you never overfill the tank and push sewage up the vent.

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.