6v to 12v VW conversion

With winter on its way, you might want to consider upping the ante by replacing your older 6v electrics with a 12v VW conversion. If you need a boost – here’s what’s involved…

You’ll often hear owners of pre-’68 air-cooled VWs complain about their rubbish electrics. We’re talking about lethargic windscreen wipers that struggle to keep your screen clear, lazy starting, real issues if you want a decent sound system and headlamps that resemble candles. Which is why lots of owners give their electrical system more of a modern feel by converting their cars from 6 to 12-volts.

VW 6v to 12v conversion

Before you start

Before you get ordering the necessary parts to carry out a 12v VW conversion, it’s worth checking that your existing 6v system is working at its maximum efficiency. Are all the earth connections good, is the dynamo putting out enough juice and is the rest of your ignition system up to scratch? You can even get 6v halogen headlamp bulbs here which might help. Bear in mind too, that by ditching all your 6v gear you’ll be affecting the car’s originality. So if you do carry out the switch, keep all your old components so if you sell your car on, you can offer the vendor all the necessary bits to return it to its factory state if they should so wish.

VW checking bad earths

Parts required

Don’t be fooled into thinking that an upgrade will just involve swapping a few bulbs and fitting a different dynamo/alternator. In reality, you will need a whole list of parts including:

12v battery

12v generator/alternator

12v coil (and condenser)

12v idle cut-off solenoid

12v wiper motor

12v horn (although you can keep your 6v one – see below)

12v headlamp and indicator relays

12v bulbs – for both inside and outside the car

12v choke, although people often fit a different carb

Cars fitted with 12v electrics have a flywheel with 130 not 109 teeth so you can’t just fit a 12v starter as the pinion shaft was different. However, most people stick with their 6v starter – it will survive for a surprisingly long time if you don’t over crank it!

Alternator conversion

If you want to go the whole hog, you might as well carry out an alternator conversion for a more constant voltage output. We offer a handy kit with everything required, including a new alteranator stand, tinware and some handy wiring for bypassing the old dynamo regulator. Check it out here.

converting VW to an alternator

Get the kit

Obviously the best option when doing a 12v conversion is to buy a kit such as the VW Heritage one offered here.


Not only does this include most of things needed to carry out the change, as well as an alternator, but also various voltage droppers which will enable you to use your existing wiper motor and carb and fuel cut-off switch.


The opinions expressed here are the personal opinions of the author and do not necessarily represent the views and opinions of VW Heritage.




4 responses to: 6v to 12v VW conversion

    1. Not an alternator. You can use a small case (diameter) 12v Porsche generator. The late 356 and 912 used those.

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