It's time to tackle our project T25 VW campervan's electrics but, as always with Wilma, it's not quite as easy as it should be, reports Nigel Donnelly

If you are a bit apprehensive about 12V electrics, a simple VW campervan conversion is the ideal place to get your head around how things work. 

At least it should be. 

As with the engine work detailed previously, there is strong evidence that Wilma has been comprehensively mucked about with, meaning that what should be a simple job of checking and understanding the installation is becoming a comprehensive rewiring job. 

My initial inspection revealed that there are in fact two fuse boxes for the habitation area of the ’van, despite the fact there there are only two lights, both of which are over the kitchen, one of which works. The only other 12V equipment is the fridge ignition, the remains of an old heating system and four 12V DIN sockets. There is also a non-functioning water system. 

The aim of this work is to understand which wires go where and do what. There is no leisure battery, so any 12V equipment in the campervan is powered by the vehicle battery. My aim is to fit a leisure battery, along with a split-charge system. The split-charge system simply ensures that power from the engine alternator charges the starter battery and the leisure battery, so you can survive for a night or two away from the sanctuary of a mains hook-up, and be able to start the ’van in the morning. There is no point connecting all my nice new wiring to the jumble of old salad that is currently in place, however, so I need to sort things out. 

What quickly became apparent was that there are two lots of wiring in place. There is a substantial and well-installed fuse box behind the driver’s seat, but it appears that it doesn’t do much. There is a smaller one under the same seat which appears to be used to bypass the original fuse box. Much of the cabling to this is messy and the feed for this runs on a single, woefully under-specified cable which is poked, unprotected through two steel bulkheads and straight onto the battery. There is no fuse at this end, which means that had either of the bulkheads managed to chew through that cable, you’d have had a bonfire on your hands. Happily, the connection to the battery had long since failed, so there was no danger, although it does explain why there were no lights in the back of the ’van either. 

The water pump fitted to the VW to feed the single tap is a bit over the top, but this has long-since been bypassed and is inoperative. There is a Truma gas heater fitted and the wiring remains, but the controls are long-since gone. 

Looking at the mess of wiring, the easiest thing is to draw a simple diagram of what is required and to rerun new cabling, labelling it all as I go. That means 12V feeds for lighting, maybe a 12V socket, and to transfer the CD player to the leisure battery so that it works without the keys in the ignition on site, and doesn’t flatten the battery during an evening’s entertaining. The fridge needs 12V supply for the ignition and also to work while driving along the road, and I will work out a less involved water supply.

The current diaphragm pump looks more like something you’d see on a fire engine, and is ludicrously over-specced for a campervan with a single cold tap. It also sits under the passenger seat, which is the place that most VW T25 conversions put the leisure battery. I shall be doing the same.

It’s not all disasters on the electrics, though. On the plus side, the mains system has a proper circuit breaker, is appropriately earthed and has been very neatly installed. The main work to do here is to change the socket faceplates to UK three-pin instead of Continental two-pin, and get a grown up to check it is all safe before using it. I will also add a mains battery charger so that the leisure battery gets topped up while on site. 

Share with friends

Follow us on

Most recent motorhome reviews

Nomad Ranger


The Practical Motorhome Nomad Ranger VW campervan review – 1 - The Kombi-based Nomad Ranger costs from £44,135 OTR – the campervan pictured is £49,985 (© Practical Motorhome)
The Practical Motorhome Bailey Autograph 75-2 review – 1 - Priced from £50,995 OTR, the Peugeot Boxer/Al-Ko-based Bailey Autograph 75-2 has a 3500kg MTPLM (© Phil Russell/Practical Motorhome)

Autohaus Ashton


The Practical Motorhome Autohaus Ashton review – 1 - This T6 VW campervan costs from £37,950 with lots of available options – this model is £46,995 as tested (© Practical Motorhome)

Rapido 665F


The Practical Motorhome Rapido 665F review 1 - Read our Rapido 665F review – it costs £51,000 OTR, or £55,169 as tested (© Niall Hampton/Practical Motorhome)
The Practical Motorhome Rimor Katamarano 95 P Plus review – 1 - You get five berths and five travel seats yet still a 3500kg MTPLM, all for under £40,000 – read our review! (© Niall Hampton/Practical Motorhome)
The Practical Motorhome Hillside Leisure Birchover review – 1 - Hillside's Birchover costs from £41,995 for the long-wheelbase camper and from £39,995 for the short-wheelbase version – with extras, the featured model costs £46,749 (© Practical Motorhome)