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Oyviny 7-way blade and 4-pin trailer circuit tester with six green LEDs in ABS housing

Oyviny 7 Way Blade & 4 Pin Trailer Light Circuit Tester

SKU CH-XS7D-EWCCT

Tests 4-pin and 7-blade trailer connectors for six light functions using bright green LED indicators on most trucks and RVs

  • FeaturesCorded Electric, false
  • Weight0.118 kilograms
  • Sports Team1 Piece
  • TypeElectrical Measurement Device
  • Tests 6 trailer light functions with bright LED indicators
  • 2-in-1 design checks both 4-pin and 7-blade connectors
  • No batteries or wiring required for simple plug-and-play use
  • Durable ABS housing with tin-plated copper terminals resists corrosion
  • Weighs 0.118 kg for easy handling and storage

2-in-1 Trailer Circuit Tester

This Oyviny tester combines 4-pin and 7-blade connectors into one device for checking vehicle-side trailer sockets. It covers six light functions including taillights, brake lights, reverse lights, turn signals, electric trailer brakes and 12V auxiliary power. Green LEDs show the status of each circuit instantly. No batteries or wiring are required for operation.

Suits DIY Checks, Not LED Systems

The tool works for most trucks, boats, campers and towed vehicles using standard incandescent lighting. It cannot test LED lighting systems or vehicles equipped with lamp-out sensors such as certain BMW, VW, Audi, Mercedes-Benz and Porsche models. Builders needing to diagnose LED circuits or sensor-equipped vehicles should look at alternative diagnostic equipment.

Six Functions With Clear Limits

Each of the six functions has a dedicated LED indicator so you can confirm taillight, brake, reverse, turn-signal, brake-controller and 12V power circuits at a glance. The tester draws power directly from the vehicle socket, so there is no internal battery to manage. It stops short of testing LED-based trailer lights or any circuit protected by a lamp-out monitoring system.

Highlights

  • Tests 6 trailer light functions with bright LED indicators
  • 2-in-1 design checks both 4-pin and 7-blade connectors
  • No batteries or wiring required for simple plug-and-play use
  • Durable ABS housing with tin-plated copper terminals resists corrosion
  • Weighs 0.118 kg for easy handling and storage

Specifications

BrandOyviny
FeaturesCorded Electric, false
Weight0.118 kilograms
Sports Team1 Piece
TypeElectrical Measurement Device

Questions about this item

Will this tester plug into the 4-pin flat connector on my truck without an extra adapter?

Yes — the unit has a built-in 4-pin male plug on one side so it connects directly to the vehicle socket.

The notes say it reads upside down on 2017 and newer Ford, GMC and Chevy models — does that mean the tester is faulty?

No, the LED layout is reversed on those vehicles; the lights still show the correct circuit status, just in the opposite order.

After I plug it in, which LEDs should glow to confirm the brake-controller output is live?

The green LED labelled for the brake circuit will light when the controller sends power to the trailer plug.

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