AOHEWEI 13 Pin Trailer Lights Plug and Socket Tester 12V Wiring Circuit Electrics Diagnostic Connector for Towing Car Caravan

Purchased this because I recently had a new 13 pin plug fitted to my caravan by the service engineer.Unfortunately the plug just fell apart when we were on a camp site. So having a few spare wires and the indicator lights not working, rather than risk blowing the electrical system on my car, I purchased on of these testers.Does the job very well and sorted my problem out without having to connect the car to the caravan, and risk damaging my car electrics.It checks the wiring circuits on the caravan to the plug ok, but it will not check the light bulbs are working.

Helped me to resolve a problem that I had with the lights on my trailer. I used it to check the wiring of the new light board that I was looking to purchase. A handy little tool!!

Works ok but have to wiggle connection to ensure led lights don't flicker.

Works well and helped to find fault to avoid expensive call out.

Sent back as didn’t work , lights randomly worked but not in correctly better off using a volt meter and a 12v battery to test pins and lights

Identified the problem straight away. Very easy to use. Recommend to all caravaners.

Bought this to test newly installed towbar electrics on my Volvo XC90. The electrical wiring used for the towbar was the genuine Volvo kit with the Volvo towbar module. In other words, the official kit recommended by the cars manufacturer.The unit is very easy to use. Install a 9 V smoke alarm type battery (not included), and then plug into the towbar, electrical socket, and check that the appropriate LEDs light up and go out when you activate brake lights, reverse lights, indicators etc.The unit can also be used the other way and test the lights et cetera on a trailer by pushing a button on the side of the unit. I can’t comment on this as I haven’t tried it, but on the face of it would appear to be very useful.So on paper it’s all good, but in use, there are a few problems. Firstly, after installing the 9 V battery, the battery cover will not reattach. This means you have to leave it off while you use the unit. Not the end of the world, but it’s likely to result in the cover getting lost at some point.More worrying is that the test LEDs on the unit for permanent and switched lives are wired back to front. At first, I thought there was an issue with my towbar wiring, but by using a multimeter against the appropriate pins, it was obvious that the towbar is correct, but the tester is wrong. And once you start needing to use a multimeter to verify what a test unit os telling you, you may as well just test the lot with a meter using one of the readily available towbar wiring pinout diagrams online.The final issue, which may be specific to this car/towbar wiring is that the pins for both left and right hand indicators always retain a voltage even when not in use. This voltage or at least the current behind it is not enough to light a conventional filament type bulb in a trailer board. However, it does illuminate the LEDs on the tester which shows as both indicators being permanently “on”, indicating a fault in the wiring that actually isn’t there in practice.The unit does what it says on the tin, and does provide a good quick check of wiring, but with the incorrect wiring of the two live feed indicators, and the false reporting of a fault on the indicator circuit on my car, I found I couldn’t really trust what it was telling me, and that I needed to manually test the connector pins on the car with a multimeter afterwards. once you go down this road, you may as well just test the whole thing with the multimeter and save the money.Given it three stars, because it does work of sorts. But I found that two of its test LEDs weren’t wired correctly to start with meaning I needed to verify and check manually what it was telling me.

Solidly built