If you’re getting a towbar fitted, the bar itself is only half the decision. The other half is the electrics: the socket on the back of your car that powers the lights on your trailer, caravan or bike rack. Pick the wrong one and you can end up with lights that don’t work, a caravan that won’t charge, or a cupboard full of adaptors. This guide explains the choices in plain English, so you know what to ask for when you get a quote.
Start with what you’ll be towing
The best electrics for you depend on what you plan to tow or carry, not just on your car. Before you ask for a quote, it helps to know:
- Is it a small trailer, a bike rack, a horsebox or a caravan?
- What socket does the trailer, rack or caravan already have? Have a look at the plug on its cable.
- For a caravan, do you need the leisure battery or fridge to keep working while you drive?
Once you know that, the rest falls into place.
7-pin or 13-pin: what’s the difference?
Single 7-pin (12N) is the traditional UK towing socket. It carries the road lights only: indicators, brake lights, tail lights and fog light. It doesn’t carry a reverse light. It’s still common on older trailers and some bike racks.
Twin electrics (12N and 12S) are two 7-pin sockets side by side. The 12N socket does the lights, and the second 12S socket supplies the extra feeds an older caravan uses. If you have an older caravan with two plugs, this is what it’s expecting.
13-pin is the newer single socket. It does everything the lights need, and it has room for extra feeds as well. With dedicated 13-pin electrics there are usually two options: all the road light functions plus a permanent live feed, or all the road light functions with a full charging system. If you tow a caravan and want the battery to charge while you drive, ask for the full charging option.
If your trailer has a 7-pin plug and your car has a 13-pin socket (or the other way round), adaptors are available. For regular use, though, it’s usually neater and more reliable to choose the right socket in the first place. If you’re not sure, tell us what you tow and we’ll recommend one.
Dedicated or universal wiring?
The socket is what you see. Behind it, the wiring that connects it to your car comes in two types.
Dedicated (vehicle-specific) electrics are plug-in wiring kits made for your exact vehicle. They connect at the points the manufacturer intended, instead of splicing into the car’s wiring. Where your car has the features, they work with its built-in safety systems while you’re towing and can switch off the rear parking sensors when a trailer is plugged in. They cost more, and some cars need coding before everything works. There’s more detail on our dedicated electrics page.
Universal electrics are the traditional way towbars have been wired for years. The socket is connected to your car’s lighting with snap connectors, after each correct wire has been found with a tester. Universal kits can be used for single, twin and 13-pin sockets. Depending on your vehicle and the electrics you choose, a universal kit may need an audible monitor (often called a buzzer). UK law requires that you’re told the trailer indicators are working, and the buzzer does that job. See our universal electrics page for more.
Does my car need factory towbar preparation?
Some dedicated kits rely on the car having factory towbar preparation. If your car doesn’t have it, a dedicated kit won’t fit, so we’d fit universal electrics instead. You don’t need to work this out yourself. We check your vehicle and confirm which electrics it needs before we fit anything.
What about coding?
Many modern cars need their software updating (coding) so they recognise the towbar electrics. Coding is what lets the car’s own towing features work, such as switching off the parking sensors when a trailer is plugged in. Where your car needs it, we do the coding as part of the fitting, so there’s no separate trip to a dealer.
A quick guide
- Small trailer or bike rack with a 7-pin plug: a single 7-pin socket is usually enough.
- Older caravan with two plugs: twin 12N and 12S electrics.
- Caravan with a 13-pin plug: 13-pin electrics, with the full charging option if you want the battery charged while you drive.
- Newer car with parking sensors and driver aids: dedicated electrics are often the better choice, with coding where the car needs it.
- Not sure: choose “Not known” on our quote form and we’ll recommend the right set-up. Still choosing the bar itself? Our types of towbars guide compares fixed flange, fixed swan neck and detachable.
Already got a towbar, but the electrics aren’t right?
We don’t just fit new towbars. If you’re moving from an older 7-pin set-up to 13-pin, need the extra feeds for a caravan, or your trailer lights have stopped working, we can come to you and sort it. Have a look at our towbar electrics repairs page.
Fitted at your home or workplace
The Towbar Man is a mobile service. Jake, who has over 18 years’ experience in the towing industry, fits your towbar and electrics at your home or workplace, so there’s no garage drop-off and no lift home to arrange. Most vehicles are done in a couple of hours. We fit mainly Tow-Trust towbars, plus other quality brands including ConWys, ECS, Brink and Oris.
Every fitting comes with a 12 month guarantee, and you pay by cash or bank transfer when the job’s done. We cover Leicestershire and the Midlands, including Leicester, Loughborough, Hinckley, Coalville, Nottingham and Derby. See all the areas we cover, or read what our customers say. You’ll find more answers in our FAQs.
Get a free quote
Tell us your vehicle, what you want to tow and your postcode, and we’ll come back with friendly advice and a free, no-obligation quote. Get your free quote here, or email sales@thetowbarman.com. You can also try our instant towbar price checker for an estimate, and we’ll confirm the exact price before booking.