I had some inconsistencies with the wiper delay on mine and could not come to a conclusion as to what the root cause happened to be. The wiper delay is driven by a rain sensor that sits in the plastic housing at the base of the rear view mirror and has a unique temprament. Sometimes the clear gasket between the sensor and the windshield starts to separate and needs replacing. Other times it is the sensor failing. I gave up and pulled the fuse, so now it operates as a normal rain delay.