Light switch

Hi,

I have a problem with the rotary switch on the headlight web on my 1972 6v dax,
Position 2 lights the headlamp and tail light but position 1 has no effect ( except stopping the indicators - so something is drawing power) the side light does not come on on position 1 which I expect should happen. I changed the generator for a modern Chinese one which had a wire less than the original - which was normal ( it said ,from memory, in the instructions) The main lights only light when the engine is running everything else works on the battery. I took it off the road a fews years back so I can't recall what it was like before the gen swap.
Any ideas ?

As far as I remember, the brake light, indicators and speedo light require the battery in order to operate.
The others will work fine on a running engine.

Maybe there's a short circuit or bad connection somewhere near the switch or earthing?

I've found a wiring diagram that shows the pin outs/connections for this switch and I'm hoping to not need to pull the petrol tank out again. I will buzz out the wiring from the rectifier to the pilot light/tail lights and post the results.