Volkswagen 6V to 12V Conversion

Whether winter has prompted you to perform an electrical upgrade, or you're new to oldtimer ownership and missing the extra volts that your more modern VW had, here is what you need to do to carry out a 6v to 12v conversion on your classic Volkswagen. 

VW fitted all vehicles up to and including 1966 model year with 6v electrics. That includes VW Beetle, VW Splitscreen Type 2, VW Karmann Ghia and VW Type 3. From 1967 model year (August 1966 onwards) Volkswagen installed a 12v electrical system in all their vehicles. 

There is no necessity to upgrade from 6v electrics. Everything still works and remains street legal (in the UK) regardless of the battery output. However, if you're getting sick of slow windscreen wipers, headlamps that flicker like candles (and tail lamps that are equally as dim), or fancy fitting a new stereo system to sing along to, a 12-volt upgrade might just be for you. 

Another factor that may influence your decision is that all modern in-car electrical components and accessories run on 12v. Phone chargers, Sat Navs, portable heaters and fans, map lights, etc. So if you plan on spending some serious hours on the road, 12 volts certainly makes sense. 

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 get 6v halogen headlamp bulbs which might help if the lighting is your primary concern. 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 a new owner all the necessary bits to return it to its factory state if they should so wish.

Don’t be fooled into thinking that an upgrade will just involve swapping a few bulbs and fitting a different dynamo/alternator.

To complete the 6v -12 volt conversion you will need:

• 12v Battery
• 12v dynamo or alternator 
• 12v coil and ignition condensor
•  12v idle cut off solenoid
•  12v wiper motor
•  12v horn
•  12v headlamp and indicator relays
• 12v bulbs for interior and exterior
• 12v choke.

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!

It is possible to fit a device called a voltage dropper to keep some of the above components as original, however, you won't be getting the full benefit of the 12-volt conversion, especially with the wiper motor. 

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 alternator stand, tinware, and some handy wiring for bypassing the old dynamo regulator. Check it out here.

We hope this guide will help you steer through a succesful conversion, or at least give you all the information you should need to make the decision as to whether a 12v upgrade is for you. 

Ian / Andy