Roy, thanks for your input. Sorry if I have not explained this very well.

1. First I discovered the rear bulb showed signs of being blown.

2. Removed burnt bulb.

3. Replaced with new bulb.

4. Front indicator starts flashing, but replaced bulb does not light up

5. Disconnect new bulb, front stops flashing

6. Remove wires going to bulb holder

7. Hold wires onto bulb terminals so we have wire 1 connected to bulb and bulb connected to wire 2

8. Front indicator flashes

9. Power is travelling through bulb but bulb is not lighting up

It is worth noting this was all working before and appears to have stopped due to burnt out bulb, a bulb which was brown inside and looked blown. Also I bought an extra bulb (x2) which I was told was 12 volt.Maybe they sold me a pair of the wrong bulbs, i.e. two 24 volt ?

My uneducated guess is that I might have 2 24 volt replacement bulbs. There is nothing on the bulb to say what volt it is. They could be mixed up easily Maybe they sold me the wrong bulb. What do you think?

Do you happen to know the ordering specs for the 12 volt 2 pin bulbs and somewhere to order them from? The ones I got were in a car spares shop.

My bus number (if any): RCL2259

Did find specs above. Its been a while.

My bus number (if any): RCL2259

If you got the bulbs from a car shop, i suspect they aer 12 volt. Change both bulbs for new 12 v bulbs and see what happens. If both work then you're ok. If not try 2 new 24v bulbs.

My bus number (if any): RML2532

IIRC the physics then if there is one 12 volt 21 watt bulb and one 24 volt 21 watt bulb in this circuit then the wattage and amps for the 24 volt bulb will be so low that you will not notice it is illuminated in an interrupted in series supply. It will however complete the circuit and allow the 12 volt bulb to light. Again IIRC If you swap the front and irear bulbs over then you will transfer the 'fault' to the other end of the vehicle.