#7 pin trailer plug plus

What’s the problem with that? Well, I don’t have the luxury of keeping my trailers in a garage – they are out in the elements – which is great if you like providing homes for bugs. The 7 pin round plug on the trailer has individual female sockets for the each pins. This is what the 7 pin round trailer plug looks like:

Why is it more reliable? One reason is that the flat connector has the female part (the part you need to protect most) covered and attached to the vehicle – but with the round connectors, it is a bit more complicated. I had one vehicle with a 12 pin socket and a trailer with a 7 pin connector and they played happily for years. I used a small 7 pin round for 10 years, and then after replacing the plug multiple times changed to 7 pin flat for the last 15 years, and I have never had a problem with a flat connector. In my personal experience the flat style plug is more reliable. It’s cool to be square (well, rectangular) All diagrams are as viewed from the Cable Side. No key (other than oversized earth pin) on the socket or plug. Identifying: Plug size is similar to an Australian 50c coin. Identifying: Plug size is similar to an Australian 20c coin. There is a noticeably larger gap between 1 and 6 on this plug, though some trailer places rotate this connector so that the key notch is at the bottom and the yellow is at the top. Identifying: Plug size is similar to an Australian 10c coin. All diagrams are as viewed from the Cable Side – see example above Small 7 Pin Round (QLD) The 7 pin flat plug will fit into a 12 pin flat socket and work perfectly, and vice versa. Thanks heaps Rick! 12 Pin Flat (The Extended Best!) It looks like the number 1 pin in my photo above (yellow) needs this treatment. Simple fix: gently press a knife blade into the split to expand it and resist the wiggle. In doing so the split brass male section of the plug closed and, being brass, did not spring back thus losing contact with the female section in the socket. After a bit I found that, as the plug is held quite securely in the socket, I was tempted to wiggle the plug from side to side to release it. Right flash stopped working, wiring all OK, connecting screws OK. If your flat trailer connector isn’t working, here’s a great fix from Rick in the comments: The Earth pin (3) is slightly further away from the camera – it is a bit lower than the rest of the pins. Black and blue wires are not connected in the above image as they were not needed for this box trailer with no brakes or aux/reverse.

The best! All diagrams are as viewed from the Cable Side. Mandatory disclaimer – I’m a programmer, not an auto electrician, so please check first 🙂 Most images are from Varta – a manufacturer of plugs, sockets and adapters sold in Australia. So every rectangular socket in Australia is compatible with every rectangular plug! On the other hand, flat connectors have only one possible pinout in Australia, one possible orientation (they aren’t half rotated), and the extended 12 pin version is even compatible with the 7 pin one.

#7 pin trailer plug plus

Plus to top it all off, sometimes the small 7 pin round is rotated so that the yellow pin is at the top! Queensland prefers the small 7 pin round, and apparently Victorians prefer a large 7 pin round that has a completely different pinout! There is also a heavy duty 7 pin round, which is different again! Why? Oh Why? And you can chuck in a couple of older 5 and 6 pin round connectors as well just to make it more confusing (I don’t think they are still in use, so I haven’t put them here). Why? Well first of all, which round one? There are at least 3 different 7 pin round connectors in use in Australia right now. If you have a round connector, commiserations. I put this here because I had a hard time finding and figuring this out for my trailers. Here’s the wiring diagrams showing the pin out for the plug and socket for the most common circle and rectangle trailer connections in use in Australia.