6v v 12v Wiring. Is there a load difference?
 

Folks,

We have taken possession of our recently purchased 1948 M47 Pickup.
The old original wiring is glaring at me and calling fire, fire......
BTW where is the fuse box on these pickups or don't they have one?

Can I replace the old wiring with a new 12v harness and will it handle the 6v amperage? Or should I spend extra coin and convert to a 12v system entirely?

Being a petrol engine we just want safe electrics (nothing fancy).

Much appreciated.

Re: 6v v 12v Wiring. Is there a load difference?
 

There is not a fuse box in the original configuration. The gauges have simple circuit breaker setups.

The wiring for a 6v system needs to be lower gauge (heavier wire) than a 12v system. Conversion to 12v is often a question of preference and perception of reliability.

Re: 6v v 12v Wiring. Is there a load difference?
 

Waynet, 6 volt harnesses are available from suppliers who serve the hobby. 12 volt can be special ordered, but will not work for 6 volt, as it is smaller gauge wire.

Re: 6v v 12v Wiring. Is there a load difference?
 

Using this simple equation P=E times I , Power equals voltage times amperage.
It will show you that if you drop the voltage in half, you will double the amperage
through the wire to produce the same amount of power. You will have a tremendous
amount of power lost in the form of hot wires. Starters require a lot of power. Running
a car on 12v using 6v wiring is fine, but not the other way around.

Re: 6v v 12v Wiring. Is there a load difference?
 

That answers a question that wanted to know for awhile. Thanks. John

Re: 6v v 12v Wiring. Is there a load difference?
 

Is the insulation deteriorated or crumbling? They used (and tried) different materials back then. Pre-war Radios for example used cloth insulation, which has held up really well. Then some manufacturers tried using natural rubber - which has turned to dust and disintegrated. Oops! Just how dangerous is the older 6 volt wiring? It certainly can be, but I'd not necessarily condemn it just on age alone.

Re: 6v v 12v Wiring. Is there a load difference?
 

Where most 6-volt cars will use a 16 AWG wire for a single load circuit, the 12-volt systems only need an 18 AWG wire. You can use 6-volt wiring for 12-volt but you can't use 12-volt wiring for 6-volt. There would be too much resistance for the lower voltage on the smaller gauge wires.

Wiring that caries a higher flow of amperage such as the generator armature wire and the battery buss wire have to be a fair amount larger in wire gauge than just 16 so I would recommend just purchasing a wire harness for the 6-volt systems. If the vehicle is changed currently or at a later date to 12-volt then nothing has to be changed.

Re: 6v v 12v Wiring. Is there a load difference?
 

I would describe the insulation being in the early stages of brittle and frayed.

Re: 6v v 12v Wiring. Is there a load difference?
 

Thanks for your advice and also others with similar sentiments.