Top 10 Best trailer light tester in 2026

Last Updated - 6/8/2026

🏆Best Choice

WINAMOO

WINAMOO Automotive Test Light with 3-48V LED Digital Voltage Display, Auto Circuit Tester with Voltmeter & Dual Color Polarity Indicate, Electric Test Pen w/Stainless Probe for Car/Truck/SUV Checker

9.8

ChoiceComparer.com Score

9.8

/ 10

Outstanding

Main highlights

•【PRECISE READOUTS & CLEAR DIGITAL DISPLAY】Bright LED display shows highly clear readings in any lighting condition, 0.1V resolution gives you reliable indication and shows you the voltage number easily & quickly. Bidirectional light emitting diode on the circuit board for easy battery load testing, red light indicates positive polarity, green light indicates negative polarity.
•【QUICK DETECTION & EXTENSIVE USE】WINAMOO auto circuit tester helps you to quickly test car battery voltage and diagnoses issues in 3V-48V systems, including alternator tester functionality of car/truck/SUV/boat charging systems. Also to inspect circuit tester integrity of headlights, taillights, turn signal circuits, faulty sockets, fuse connections and more.
•【SHARP PROBE & ANTI-LOST PROTECTIVE SLEEVE】Sharp stainless steel probe for piercing insulation with ease, also for hard to reach tight areas. Integrated anti-lost protective sleeve to secure the probe during storage and safeguarding against damage, making sure no stab and wound and won't be lost wherever you go.
•【EXTENDED SPRING WIRE & LARGE ALLIGATOR CLIP】High quality 96 inch long enough spring wire increases flexibility to access across broad areas when testing. Attaching with large crocodile clip for easy single-handed operation, which is boosting the efficiency for car battery capacity checks and beyond.
•【ULTRA-DURABLE & SAFE CONSTRUCTION】This voltage tester pen adopts ergonomic handle for comfort and safe grip. Constructed with premium ABS body with higher transparency, shatter-proof and durable. Ensuring reliable battery meter and circuit analysis for safe operation, making them an essential tool in electrical troubleshooting.

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$8.45

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WUSHIXAN

WUSHIXAN Trailer Light Tester, 7 Pin Trailer Plug Testerwith Red LED, 7 Way Trailer Plug Testerfor Diagnosing and Fixing Trailer Socket Circuit Problems

9.7

ChoiceComparer.com Score

9.7

/ 10

Outstanding

Main highlights

•【HIGH QUALITY】Trailer Tester is Made of High-quality ABS Plastic and Copper, with a Black Matte Exterior Shell for Optimal Weather, Corrosion and Impact Resistance for Long-term Use.
•【MULTI-FUNCTION】7 Pin Trailer Tester can Test Tail Lights, Brake Lights, Reverse Lights, Turn Signals, Brakes and Auxiliary Power.
•【COMPATIBILITY】Trailer Wiring Tester is Compatible with Standard 7-way Blade Trailer Outlets. 7 Pin Trailer Plug Size: 5.2x2.96x1.63 Inches (13x7.5x4.1CM).
•【SUPERIOR CONDUCTIVITY】 7 Way Trailer Plug Uses High Quality Brass Pins to Ensure a Safe and Stable Electrical Signal Connection between the Plug and the Trailer. The Trailer Light Adapter Features 6 Bright LED Indicators. Each Indicator is Clearly and Distinctly Labeled, Allowing you to Quickly Identify Working and Faulty Circuits at a Glance.
•【EASY TO USE】 Plug 7 Prong Trailer Plug into the Trailer or Adapter, Turn on the Lights, and Check the Easy-to-read LEDs, Plug and Play.

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$7.99

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OPT7

OPT7 7 Pin & 4 Pin Circuit Tester Adapter w/ 6 LED Indicators, 7 Way Blade to 4 Way Flat Trailer Connector w/Secure Tab for Pickup Truck Trailer Tow Hitch, 5.3" Long x 2.36" Diameter

9.5

ChoiceComparer.com Score

9.5

/ 10

Outstanding

Main highlights

•[2-IN-1 DESIGN] Combines 4-way circuit tester and 7-way trailer light tester, suitable for most trucks.
•[ADAPTER FUNCTIONALITY] Converts 7-pin output to 4-pin flat adapter, connecting 4-way trailer light plug.
•[6 LIGHT FUNCTIONS] Testing, brake lights, reverse lights, turn signals, electric trailer brakes, and 12V auxiliary power.
•[BRIGHT LED INDICATORS] Each function has a dedicated LED light for easy troubleshooting.
•[QUICK AND EASY TESTING] Simplifies testing of trailer circuits for both 4-pin and 7-blade connectors. Fully covered by our free 30-day warranty, offered only by OPT7.

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$17.99

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ONLINE LED STORE

True Mods 4-Way Flat Trailer Wiring Tester [Nickel-Plated Copper Terminals] [Male & Female] [Continuity Test] 4-Pin Trailer Light Wire Circuit Tester

9.4

ChoiceComparer.com Score

9.4

/ 10

Excellent

Main highlights

•STRAIGHTFORWARD TRAILER LIGHT TESTING - Simply plug the tester inline between the tow vehicle and trailer, turn on the lights and check the easy to read LEDs.
•ISOLATE PROBLEMS QUICKLY- By effectively splitting the trailer wiring harness in half, problems can be quickly traced to the tow vehicle side or the trailer side wiring.
•NO TOOLS NEEDED - Plug-n-play design means you don't need anything else to effectively test your trailer light harness.
•LONG LASTING CONSTRUCTION - Designed to be weather, corrosion, and impact resistant for years of reliable service.
•CONVENIENT COMPACT DESIGN -The two-sided design means you can leave it plugged in or store it conveniently in your glove box, door pocket, or tool box.

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$6.99

$7.50

-7%

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Oyviny

Oyviny 4-Way Flat Trailer Wiring Tester 4 Pin Male and Female Trailer Tester with Bright Indicators, Double End Design 4 Pin Trailer Light Tester for Turn Signal Tail Lights Trouble Shooter

9.2

ChoiceComparer.com Score

9.2

/ 10

Excellent

Main highlights

•4 Way Trailer Tester: Using this 4 pin trailer plug tester to confirm proper function of your vehicle’s trailer wiring harness, excellent for diagnosing trailer light issues, lets you know where in the system there is a problem instead of guessing; It also acts as a standard 4-Pin male and female trailer connector to connect standard 4-pin trailer wire
•Plug and Play: This 4 pin trailer plug tester is easy to use, just plug the tester into the 4 pin flat trailer connector on your tow vehicle and trailer to test taillights and turn signals for proper operation
•Bright LED Indicators: This 4-way trailer circuit tester features a LED light for each electrical functions, turn on the lights and check, you can easily read the LEDs and find out which wiring has a problem
•Durable Construction: 4 pin trailer socket tester is made from durable ABS plastic, which will never rust or corrode; Tin-Plated copper terminals makes great conductivity; Female end tester comes with a rubber dust cover to protect the terminals when not in use
•Compact Design: Small size trailer plug tester is convenient for storage, allows you store in your tool box, glove compartment or anywhere to be ready when you need it; Take this tester to be your assistant when needed wherever you go

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$11.99

$12.99

-8%

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Oyviny

Oyviny 7 Pin Trailer Plug Tester & 4 Pin Trailer Tester with Double-Sided LED Indicators, Trailer Light Tester for Boat Trailer RV Truck Camper, Not Suitable for Vehicle with Lamp Out Sensor

9.1

ChoiceComparer.com Score

9.1

/ 10

Excellent

Main highlights

•2 in 1 Design: This trailer wiring tester combines both 4 pin flat and rv blade 7 pin trailer light tester, allows you to test both the 4 and 7 pin trailer connectors; Note: This trailer tester does NOT work with vehicle has a lamp-out sensor
•Upgraded Double-Sided LED Indicators: 4pin & 7 pin trailer circuit tester designed with LEDs on both sides, Unlike the other testers only have one side leds, which make it hard to read; A great tool to help troubleshoot issues or verify you have install or fixed your trailer plug correctly
•6 Light Functions: Versatile trailer connector tester can be used to test 6 separate trailer light functions, quickly confirm the functionality of taillights, brake lights, reverse lights, turn signals, electric trailer brakes and 12V auxiliary power on your vehicle
•Bright LED Indicators: Trailer hitch tester equips a LED light for each electrical function; Plugging the light tester and check, you can easily read the green LEDs and find out which wiring has a problem
•Durable Construction: For long-lasting use, this 7 blade RV trailer tester is made from durable ABS plastic, which will never rust or corrode, Tin-Plated copper terminals makes great conductivity
•Simple to Use: No batteries or wiring needed; 7 Blade & 4 Pin Tester is easy to use, ergonomic design is convenient for plugging in or unplugging; Widely used to test trailer light circuits on most Trucks, Boats, Trailers Campers, Caravans, Food Vans and other Towed Vehicles

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$18.99

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CURT

CURT 58272 7-Pin RV Blade Trailer Wiring Towing Vehicle Socket Tester, Orange

8.9

ChoiceComparer.com Score

8.9

/ 10

Great

Main highlights

•VERSATILE — Quickly and confidently confirm the functionality of your vehicle's trailer wiring harness with this connector tester for the taillights, brake lights, reverse lights, turn signals, electric trailer brakes and auxiliary power
•SIMPLE TO USE — For each electrical function, an LED lights up indicating a good signal. Just plug the wiring tester into your vehicle's socket and have a helper check the LED signals as you activate them from the driver's seat
•EASY GRIP — Plugging in this 7-way trailer light tester into your vehicle is easy with its ergonomic design. It features two hooks on either side of the tester for a better grip when plugging in or unplugging
•LONG-LASTING LEDS — To produce a bright, easy-to-read signal and ensure long-lasting use, this vehicle-trailer wiring tester is constructed with LED diodes
•DURABLE HOUSING — To resist the elements and maintain reliable performance, the housing of this tow wiring tester is made from durable black plastic that will never rust or corrode

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$19.95

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Innovative Products of America

Innovative Products of America #9101 Light Ranger MUTT (7-Way Spade Pin Style with Adapter) Trailer Tester

8.8

ChoiceComparer.com Score

8.8

/ 10

Great

Main highlights

•Simulates turn signals, brake lights, and 12V power to test trailer lighting and brake systems
•Standard 7-way spade connector; includes 3-way adapter for 4-pin, 5-pin, and 6-pin trailer plugs
•Auto resetting breaker, water-resistant, and built in the USA for reliable use in shop or field environments
•Tests trailer-side electric brake function
•Includes 500mA battery charger; Battery not included: requires 12V (Group 14) battery (approx. 7.75″ L × 5″ W × 6.25″ H)

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$194.63

$231.95

-16%

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BDZMC

4 Pin Trailer Plug Tester, 4 Way Flat Trailer Circuit Tester with LED Indicators, Straight Trailer Light Wiring Testers, Trailer Tester Connector for Turn Signal Tail Lights Trouble Shooter

8.6

ChoiceComparer.com Score

8.6

/ 10

Good

Main highlights

•【4-Way Trailer Tester】:This 4-pin trailer plug tester is used to quickly track whether your trailer is wired correctly, to test whether the trailer's taillight, the right light, left light, turn signal, and brake light are working properly, and troubleshoot and ensure your driving safety.
•【Plug & Play】:This 4-pin trailer plug tester plug and play. Just insert the 4-way trailer plug tester into the connector, then operate the trailer's taillight and turn signal, turn on the light observe the LED light, and show the green light when there is electricity, indicating that it is working normally.
•【Sturdy Construction】:The 4-pin trailer connector is made of ABS plastic material, which is strong and sturdy, has corrosion resistance and impact resistance, and is not easy to rust, ensuring long-term use. With TAIL, LT, and RT lights, easy to read and see which lines have problems.
•【Portable Design】:This trailer-led indicator tester is small enough that you can put it in your pocket, toolbox, glove box, or anywhere else. And also equipped with a hanging hole and can be hung on a key chain for easy carrying and storage.
•【Wide Application】:This 4-way trailer circuit tester is suitable for most vehicles, such as trucks, trailers, boats, campervans, and other vehicles, and can be used to test the operation of various lights. DC: 6-24V.

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$4.69

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ONLINE LED STORE

True Mods 5-Way Flat Trailer Wiring Tester [Nickel-Plated Copper Terminals] [Male & Female] [Continuity Test] 5-Pin Trailer Light Wire Circuit Tester

8.5

ChoiceComparer.com Score

8.5

/ 10

Good

Main highlights

•STRAIGHTFORWARD TRAILER LIGHT TESTING - Simply plug the tester inline between the tow vehicle and trailer, turn on the lights and check the easy to read LEDs.
•ISOLATE PROBLEMS QUICKLY- By effectively splitting the trailer wiring harness in half, problems can be quickly traced to the tow vehicle side or the trailer side wiring.
•NO TOOLS NEEDED - Plug-n-play design means you don't need anything else to effectively test your trailer light harness.
•LONG LASTING CONSTRUCTION - Designed to be weather, corrosion, and impact resistant for years of reliable service.
•CONVENIENT COMPACT DESIGN -The two-sided design means you can leave it plugged in or store it conveniently in your glove box, door pocket, or tool box.

View offer on:

$6.99

$7.50

-7%

Check Price

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