This system is only working periodically. Can anyone tell me A) Location of Sensor B) Could this be caused by blocked or dirty sensor C) The best way to repair short of taking to the dealer.

If the Rain Sensor is not working, the speed is constant as if running in position II onthe switch, or Normal speed.

 

your is 210 or 211?

the rain sensor is located just behind the base of the rearview mirror.

it cannot be blocked (not unless you put some sticker on it), and cannot be dirty because it is sealed by the glass and cover inside.

the rain sensor will work if it detects the presence or water on that sensor via refraction of light.

try putting the switch on first position (engine hood must be close), and sprinkle some water on it.

the wiper only works if theres a water on it (3 actuations or more depending on the presence of water).

position 2 is intermittent function. rain sensor is bypassed.

 

Thanks fr the response, Sleep. My car is a W210. On the W210, the position I is the Rain Sensor position, II is for normal speed and III is fast. When in position I (rain Sensor mode), the wipers run at the same speed as position II (Normal) and run constantly - not as it "senses" the rain. I did notice just the other day, that my Rain Sensor was working correctly. However, that was short lived.

Our rainy season is just beginning here in Northern California, but will be fairly consistent until April. I hope I can get these things working. With the number of miles I drive each year, this is a nice option to have working properly. Besides, I hate for anything on my cars to not work.