This tester has one side to connect the 7-pins plug of a trailer and another side to connect the 7-pins socket of a car. This tester indicates quickly if a failure concerns the wiring of the car or the wiring of the trailer.
eBay
2025 NEW Fiber Optical Red Light Pen Rechargeable10mw 30mw 50mw Visual Fault Locator VFL Fiber Optic Cable Tester type-c
Aliexpress UK
Test every car every pin socket functions: open the left turn signal, the tester Yellow No. 1 indicator will light up if the LED is not lit, the line connection error or a bad line. This tester has one side to connect the 7-pins plug of a trailer and another side to connect the 7-pins socket of a car.
eBay
Portable Type-C Cable Tester with 24-Pin Full Detection Dual Head LED Indicator for Type C Fast Charging Cable
Aliexpress UK
To do this, you simply have to insert the tester into the socket or plug to be tested, press the test button and a clear diagnosis is made via the LED display. This adapter is a lighting and cable tester for trailers and towing vehicles.
eBay
COMPTYCO AUA-G510B Optical Power Meter Visual Fault Locator LED Light FTTH Optical Fiber Testing Tool 3-in-1 Fiber Optic Tester
Aliexpress UK
This tester is for a trailer/caravan and tow bar socket/plug checker. Automotive13 Pin Towing Trailer Tow Bar Caravan Light Wiring Circuit Tester Plug Socket UK. To do this, you simply have to insert the tester into the socket or plug to be tested, press the test button and a clear diagnosis is made via the LED display.
eBay
COMPTYCO AUA-M70/M50 Mini OPM 4 in 1 Optical Power Meter Visual Fault Locator Network Cable Test optical fiber tester
Aliexpress UK
Automotive7Pin to 13Pin Towing Trailer Tow Bar Caravan Light Wiring Circuit Tester Plug Socket UK. This tester is for a trailer/caravan and tow bar socket/plug checker. -Just plug the tester in the 7 pin socket or the 7 pin plug of the trailer or caravan and press the yellow button on the side of the tester.
eBay
Pro3000 Network Cable Tester with Inductive Amplifier, Audio Generator & Tracer – Cable Testing Tool for Networks
Aliexpress UK
Just plug the tester in the 7 pin socket or the 7 pin plug of the trailer or caravan and press the yellow button on the side of the tester. This 7 Pin Tester is designed to indicate a failure in the wiring on both towing vehicles and trailers/caravans etc.
eBay
Best 0.1MHz-1.7GHz TCXO RTL SDR Receiver R820T2 USB RTL-SDR Dongle with 0.5Ppm TCXO SMA MJZSEE A300U Tester
Aliexpress UK
This tester has one side to connect the 7-pins plug of a trailer and another side to connect the 7-pins socket of a car. This tester indicates quickly if a failure concerns the wiring of the car or the wiring of the trailer.
eBay
Visual Fault Locator Fiber Optic Tester Pen 10mW 20mW 30mW | FTTH Tool with Free Patch Cord + Flange Adapter | Fiber Optic VFL T
Aliexpress UK
Lighting and cable tester for trailers and towing vehicles. This convenient tester makes locating cable faults on trailers and towing vehicles quick and easy. The color of the faulty cable is indicated by an LED indicator on the device.
eBay
FNIRSI LPM-10A Network Cable Tester Multifunction Wire Tracer Line Finder with RJ45/RJ11 Length/POE/Port Flash Test
Aliexpress UK