The complete definitive answer to your quandary was posted in the New Zealand Hot Rod Magazine in the mid 70's. Here is the answer to everybodies problems......hope it helps. (Don't bother thanking me, just send me cash )

Everything you wanted to know about auto electricals.

I will now reveal to you everything you wanted to know about electricity. Forget all that nonsense about magnetic fields and the flow of electrons along a conductor, for it is just that, nonsense…….a myth put about by Auto Electricians to support their lavish lifestyles at your expense. The reality is…….Smoke!

When you think about it, it all becomes startlingly obvious. Smoke makes all electrical things function, and if the smoke escapes the component stops working. For example, the last time you had to grovel under your car to replace the starter motor, didn’t it start smoking before it stopped working? Of course it did!

The wiring loom in your car carries smoke from one device to another, pumped around the system by the dynamo, and when a wire springs a leak it lets all the smoke out and everything stops. The starter motor requires lots of smoke to work properly, so it has a very thick wire going to it.

The battery stores up lots of smoke dissolved in the battery acid, which is why they were once called accumulators, until it became apparent that we unwashed home mechanics would twig to the secret. Naturally, if you try to store too much smoke in your battery it will escape through those little holes in the top, which is why those newfangled batteries with sealed tops explode when they get too much smoke in them.

With regard to Joseph Lucas and his wrongfully sullied reputation, why is he so maligned? Why are Lucas components more likely to leak smoke than, say, Bosch or Marrelli? It’s because Lucas is British, and British things always leak. British motorcycles leak oil, British sports cars leak rain, British hydrolastic units leak fluid, and British Governments leak military secrets.

So, naturally, British electrical components leak smoke.