Shoreline Marine LED 4-Way Trailer Circuit Tester

Shoreline Marine LED 4-way trailer circuit tester — plug-in design, tests tail, turn signal, and brake lights, bright LED indicators, ~1oz. Black.

The Shoreline Marine LED 4-Way Trailer Circuit Tester plugs directly into your trailer's 4-way flat plug to quickly identify wiring faults. Bright LED indicators confirm tail light, turn signal, and brake light function at a glance — visible even in direct sunlight. Simple plug-in design requires no tools and takes seconds to use. Durable construction for repeated use in the field.

Key specs

• SKU: SM020
• Connection: 4-way flat plug
• Tests: Tail lights, turn signals, brake lights
• Indicators: Bright LED (visible in sunlight)
• Color: Black
• Weight: ~1 oz

Why it works

Trailer wiring faults are one of the most common roadside issues for boaters, campers, and anyone towing — and they're almost always discovered at the worst time. A 30-second plug-in test before every trip catches faults before they become a problem on the road or at the boat ramp.

Ideal for

Boaters, campers, and anyone who tows a trailer and wants a fast, reliable way to verify trailer light function before hitting the road.