I had the same problem b4,after I read somewhere,I added -ve grounding myself using thick wires and connectors,less than Rm15 and the problem is solved.

Look for the -ve wire(black) from the headlamp unit bolted to the car body,connect this wire to the -ve terminal of the battery using connectors and wires you bought.be careful not to mix up +ve and -ve.else,disaster will happen.

Haha,seems to be a common problem,just changed mine too,cost Rm45 inclusive of labour(Mitsuboshi belt) and the noise gone.