failed left turn indicator

[hocky4711]

I have a 1994 C180 and recently, the left turn indicator would not click, click, click as it blinks(from inside the car). The right turn is ok. Then there is a continuous humming/buzzing sound from behind the dash at the same time when I push down the indicator stalk for a left turn. Once a while, it works if I play around with the stalk. What can be wrong? Is it the bulbs(front or back), the fuse or the switch or the actual electronic relay? This car has also lost most of its power and even with 98RON premium, it is hard to drive especially in hilly areas or with more than 3 passengers. Would this be auto problems or engine problems or other parts of the car like the fuel pump, OGA or ECU? Please help with your ideas and suggestions, thanks. :?: :?: