Repair & maintenance guides

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.

NMEA 2000 Network Basics and Troubleshooting (Plus Chartplotter Updates)

Understand the backbone, terminators, power tap and drop cables that tie your chartplotter, engine data, GPS, depth and autopilot together, then track down why a device keeps dropping off. Finish by updating chartplotter and device software the safe way.

Outboard Stator and Rectifier/Regulator: Symptoms, Safe Owner Checks and When to Hand Off

Most outboards charge the battery with a stator under the flywheel and a rectifier/regulator. Learn how to read the symptoms of undercharging, overcharging and intermittent charging, what voltage checks and inspections an owner can safely do, and which tests and repairs belong to a technician with the service manual.

Power Trim Only Goes Up or Only Down: Relays, Switches and Wiring

When your outboard or sterndrive trims one way but not the other, the cause is usually electrical: a relay, a switch, a corroded plug or a wire. Learn how the up and down circuits work, how to swap-test the relays, how to tell the helm switch from the cowl switch, and how to tell an electrical fault from a hydraulic one.

Powering a Big Boat Sound System: Amplifier Draw, an Audio Battery and Charging

Work out how much current your amplifiers really pull, size a dedicated audio battery, keep it charged with an automatic charging relay or isolator, and fuse and wire it so a long day of music never leaves you unable to start the engine.

Remote Boat Monitoring: Bilge, Battery, Shore Power and GPS Alerts on Your Phone

Choose, install and set up a system that texts you when your unattended boat is taking on water, losing battery or shore power, or moving without you. Covers cellular versus satellite, what each sensor really tells you, wiring it so it stays on, sensible alert settings and what happens to your location data.

Satellite Internet on Your Boat: Starlink Plans, Mounting, Power and Wiring

An owner's guide to putting Starlink aboard: which plans allow coastal, offshore and in-motion use (as of October 2026), how much battery it eats, 12-volt versus inverter power, where to mount the dish, and how to route and seal the cable without leaks.

Shore Power Adapters and Y-Splitters: When a 30A or 50A Adapter Is Safe, and When It Isn't

Pigtail adapters and Y-splitters let a boat plug into a pedestal that doesn't match its inlet, but the wrong one, or the right one used carelessly, can overheat, trip the marina's ground-fault protection or start a fire. Learn the difference between 30A 125V, 50A 125V and 50A 125/250V, which adapters are reasonable, how to keep loads safe, and how to check connections for heat.

Shore Power Cord Ends: How to Judge a Cord, and When to Replace the Plug or the Whole Cord

Burned blades, a hot plug or a cracked locking ring don't always mean a brand-new cord, but sometimes they do. Learn how to inspect a shore power cord and its ends, decide between a replacement end and a new cord, what a proper sealed marine connector looks like, which parts of the job are safe for an owner and when the work belongs to an ABYC-certified electrician, plus the habits that make cord ends last.

Shore Power Inlet and Cord Upgrades: Burned Plugs, Better Connectors and Safe Adapters

Why shore power plugs and boat inlets overheat and burn, how to spot an inlet that needs replacing, what newer connector designs offer, and how to choose, size and care for cords and adapters. You inspect and buy the right cord; an ABYC-certified marine electrician replaces the inlet and its wiring.

Shore Power Safety: Cords, Inlets, Burned Plugs and Electric Shock Drowning

An owner's inspection routine for your shore power cord, plugs, boat inlet, galvanic isolator and ground-fault protection, plus the right way to plug in and the facts about Electric Shock Drowning. This guide is for looking and testing only; any electrical repair belongs to an ABYC-certified marine electrician.

Start Isolation for Your ACR: Stop the Chartplotter and Stereo from Rebooting at Engine Start

If your plotter, radio or stereo reboots every time you turn the key even though you have two batteries and an automatic charging relay, the relay may be tying the house battery into the cranking dip. Learn how start isolation and dual-circuit battery switches keep the electronics on their own battery, how to find and test the start-only wire, and what to check after the job.

Switching to Lithium (LiFePO4) Boat Batteries: What Changes and When It's Worth It

What really changes when you swap lead-acid for lithium iron phosphate (LiFePO4) batteries on a boat: the battery management system, charger settings, protecting the alternator with a DC-DC charger, not mixing chemistries, cold-weather charging, and which jobs (trolling, house, starting) suit lithium. House-bank conversions should be designed and installed by a qualified marine electrician.

Testing Your VHF Antenna and Coax: Radio Checks, SWR, Connectors and Mounts

Most weak or scratchy VHF radios have nothing wrong with the radio. Learn how to test the whole antenna system, from a proper radio check and a DSC test call to a multimeter and SWR meter, how to find corroded connectors and wet coax, and when to replace the cable, antenna or mount.

Trim Gauge Reads Wrong or Not at All: Testing and Replacing the Trim Sender

When the trim gauge sticks at full up, reads backward or jumps around, the cause is usually the sender at the engine, a corroded wire or a bad ground, not the gauge. Learn how the sender works, how to test the gauge and sender with a meter, how to adjust or calibrate it, and when replacement is a shop job.

Underwater LED Lights: Care, Leaks, Corrosion, Wiring and the Rules

Keep underwater LED lights bright and your hull dry. Learn the difference between through-hull and surface-mount lights, how to clean growth off the lens without damaging it, what to check for leaks, wiring, fusing and bonding, when the boat has to be hauled, and why the lights should not be on while you're underway.