Left Turn Signal Light On Tachometer Not Flashing

I have a problem with my left turn signal marker in the tachometer of my 240z. The problem first started last night when i decided to turn all the lights on the car. The left marker light of the car lighted up continuosly without turning the turn signal switch to the left or to the right. If i shut the light off and move the lever to right or left it does light intermittently as it should. All the four turn signal lights are working perfectly outside of the car.

In view of the above, the problem seems to be on the the tachometer itself, do you think it is making a false contact and it is the reason why it is not working correctly.

Please advise.