I just had windshield replaced and the new windshield had the "Rain Sensor" already installed in the new windshield. The installer wanted to check if it was working before he left and I couldn't figure out how to turn it on. I had never thought about it before. How do you activate the the rain sensor so the wipers come on or is it some other kind of sensor?

 

Turn the wiper stalk handle forward one click. The wiper will do a single swipe (and each time the car is turned on with the wiper in Sensor Mode). Then spray some water on to check that it is working.

 

Thanks that was it.