Noticed the other night that i have no lights on the rev counter, thought it would be a case of just changing the bulbs ! On closer inspection both bulbs look ok however there are 4 wires coming from the harness, Brown & Blue are redundant !
Green/white wire splits to 2 blue for each bulb & black/yellow splits to black/yellow for each bulb !
Having checked wiring diagram it looks like i must have a later harness as the tacho with the brake light failure bulb has 4 wires & mine doesnt have this light !!! So looks like it was wired up incorrectly, what i can make out from the diagram is mine should be using the blue & black/yellow wires only