We take cryptocurrency — so the coins you hold can buy real hardware.Pay in crypto, spend it on real hardware. Free insured shipping worldwide over $399. Plain, unbranded boxes, sent from Germany.Free insured shipping over $399. Your rate is locked for 30 minutes once checkout opens.Rate locked 30 minutes. Every item sealed, serial-checked and covered by a 24-month warranty.Sealed, 24-month warranty.

Saved items Sign in
Oyviny double-sided LED trailer tester with 7-pin and 4-pin connectors

Oyviny 7 Pin & 4 Pin Trailer Tester Double-Sided LED Electrical System Tool

SKU CH-C924-NHA0J

Tests 4-pin flat and 7-pin blade trailer connectors with double-sided LED indicators for six light functions

  • Features7 Way Blade & 4 Pin Trailer Tester, false
  • Sports Team1 Piece
  • Tests both 4-pin flat and 7-pin blade connectors with one tool
  • Double-sided LEDs show results from either angle for easier reading
  • Checks six light functions including brakes, signals and 12 V auxiliary
  • Green LEDs per circuit pinpoint wiring faults instantly
  • ABS body with tin-plated copper terminals resists corrosion and ensures conductivity

2-in-1 Trailer Wiring Tester

This Oyviny tester combines a 4-pin flat connector and a 7-way RV blade connector in one tool. It is built for owners of trucks, boats, campers, caravans and food vans who need to verify trailer light circuits before towing. The unit requires no batteries or external wiring to operate. It is not suitable for vehicles equipped with a lamp-out sensor.

Six-Function Circuit Verification

The tester checks six separate trailer light functions: taillights, brake lights, reverse lights, turn signals, electric trailer brakes and 12V auxiliary power. Green LEDs illuminate for each active circuit, letting you confirm correct operation or pinpoint a wiring fault. The tool provides a straightforward pass-or-fail indication for every function tested.

Double-Sided LED Readout

LEDs are mounted on both faces of the tester body, so the status lights remain visible from either side while you stand at the hitch. This layout removes the need to peer around the connector to read a single-sided display. The ABS plastic housing resists rust and corrosion, while tin-plated copper terminals maintain reliable conductivity over repeated use.

Highlights

  • Tests both 4-pin flat and 7-pin blade connectors with one tool
  • Double-sided LEDs show results from either angle for easier reading
  • Checks six light functions including brakes, signals and 12 V auxiliary
  • Green LEDs per circuit pinpoint wiring faults instantly
  • ABS body with tin-plated copper terminals resists corrosion and ensures conductivity

Specifications

BrandOyviny
Features7 Way Blade & 4 Pin Trailer Tester, false
Sports Team1 Piece

Questions about this item

Will this Oyviny tester work with the 7-pin blade and 4-pin flat connectors on my older boat trailer?

Yes, the 2-in-1 design combines a 7-way RV blade connector and a 4-way flat connector, letting you test both types on most trucks, boats, trailers, campers and other towed vehicles.

How can I verify the tester is showing the correct light functions after I plug it in?

Plug the tester into the vehicle socket; six green LEDs — one each for tail lights, brake lights, reverse lights, turn signals, electric trailer brakes and 12V auxiliary power — will illuminate to confirm each circuit is working.

Does the package include any batteries or a separate 5-pin adapter for my utility trailer?

No batteries or wiring are needed — the unit draws power from the vehicle — and the box contains only the double-sided LED tester itself; a 5-pin adapter is not included.

Also in this aisle

People compared these

Same shelf, same checkout — eight coins and a 30-minute rate lock.