Auto rain sensor

[Avgasandy]

Hi can anyone tell me where to look,
I recently changed my front wiper blades to the new style wiper blades and what a difference these have made, the only downside is my auto rain sensor does not seem to operate correctly anymore. When you select first position on wiper stalk the wiper sweeps the windscreen twice and then thats it it stops no matter how hard it rains, i might get 1 more sweep after a while but by that time i have usually changed to 2nd position on the stalk to regain visability.
The car is the mk 2 hdi
Anyone any sugestions, looked at my old wiper blades and they look like standard old blades.
Thanks for looking

[DaiRees]

Is there and echo in here??

[Jimmy]

The auto wipers on my D9 are awful. so ure not alone, i doubt that the wipers would make a differance. Perhaps giving the sensor a good clean may help. I think it works by beaming a light ray out and then when it's distorted by water it fires the motors.