If it is a brake light related problem, the indicator light is on only after the brake is applied. I think you can narrow down the problem area by turning on the lights one area at a time to see which area causes the indicator light to be on: brake lights, head lights, left parking lights, right parking lights, all parking lights, etc. This is just a theory based on the circuit from my memory. If I am wrong, I am possibly not too far off.

David