Motorbike accent lights

Yes, that general circuit should work OK.

 

Relays can be tricky. Read the data sheet and app notes carefully.

 

Me too added some blue LED lights on my bike. I did everything correctly but still it wasn't worked. After analyzing everything still unable to the find root cause of the problem and finally one my uncle who is senior electrician NJ helped me solve the problem.

 

In the wiring diagram, the group of diodes on the left will not light. They are wired "back to back", i.e. in each series pair one diode will be back biased regardless of applied polarity. The diode group on the right of the diagram looks fine.

 

It is noted on the circuit diagram.