Blog

Every spring, boats start rolling into our shop with the same issues—electronics cutting out, sonar interference, dead batteries, or wiring that looks like it barely survived last season.

The problem usually isn’t the electronics themselves. It’s the wiring.

Modern fishing boats rely on clean power and proper electrical design more than ever. Forward-facing sonar, high-draw trolling motors, lithium batteries, and large displays all demand more from a boat’s electrical system than older setups ever did.

Here are the most common marine wiring mistakes we fix every spring, and what you can do to avoid them.

1. Undersized Power and Ground Wires

One of the most common problems we see is wire that’s simply too small for the load it’s carrying.

High-draw electronics and sonar units require consistent voltage. Undersized wire leads to:

• Voltage drop
• Flickering or rebooting screens
• Sonar interference
• Poor performance under load

How to avoid it:
Always size wire based on current draw and total wire length, not what “worked before.” Modern electronics demand heavier gauge wiring than many factory boats were designed for.

2. Sharing Grounds Between Electronics and High-Draw Accessories

This is a big one—and a major cause of interference.

We regularly see electronics sharing grounds with:

• Trolling motors
• Bilge pumps
• Livewell pumps
• Lighting circuits

That shared ground introduces electrical noise that shows up as lines, clutter, or instability on sonar screens.

How to avoid it:
Run dedicated power and ground circuits for marine electronics, separate from pumps and motors. Clean power = clean sonar.

3. Corroded or Improper Connectors

Twist-on connectors, household butt connectors, and cheap terminals don’t belong in a marine environment.

Over time, they lead to:

• Hidden corrosion
• High resistance
• Intermittent failures that are hard to diagnose

How to avoid it:
Use marine-grade connectors, proper crimping tools, and sealed heat-shrink connections. A connection is only as good as the terminal holding it together.

4. No Fuse Blocks or Poor Circuit Protection

We see plenty of boats where electronics are:

• Stacked onto a single fuse
• Tied directly to the battery
• Protected by whatever fuse happened to be available

This isn’t just unreliable—it’s unsafe.

How to avoid it:
Install proper marine fuse blocks or power distribution systems sized for each circuit. Every electronic device should be individually protected.

5. Mixing Lithium and Lead-Acid Without a Plan

Lithium batteries have changed marine power systems—but only when installed correctly.

Common issues include:

• Incorrect charging setups
• Improper isolation
• Incompatible onboard chargers

How to avoid it:
Lithium batteries require intentional system design. Charging, wiring, and battery management must all work together. Mixing battery types without a plan leads to headaches fast.

6. Poor Cable Routing and No Strain Relief

Loose wiring that rubs against sharp edges or flexes constantly will fail—sometimes sooner than later.

We often find:

• Unsupported wire runs
• Tight bends near connectors
• Cables pinched under decks or lids

How to avoid it:
Secure wiring properly, protect it from abrasion, and leave service loops where needed. Boats vibrate—your wiring needs to be built for it.

Why These Problems Show Up Every Spring

Most wiring issues don’t fail immediately. They show up after:

• A season of vibration
• Cold winters
• Heavy current draw
• Moisture exposure

That’s why spring is when problems surface—and why fixing wiring before the season starts saves time and money.

How Deep V Rigging Approaches Marine Wiring

At Deep V Rigging, wiring isn’t an afterthought—it’s the foundation of every install.

We focus on:

• Clean, dedicated power systems
• Proper wire sizing and routing
• Marine-grade components only
• Installations built for real-world fishing conditions

Whether you’re running advanced sonar, lithium batteries, or a full electronics upgrade, the goal is the same: reliable performance every time you hit the water.

Thinking About an Upgrade This Season?

If you’re planning new electronics—or already dealing with electrical issues—now is the time to address them before the spring rush.

Contact us to schedule an inspection or get a custom quote for your boat.
Reliable wiring means more time fishing—and fewer problems on the water.