Originally Posted by Spacebug
....I also don't think I can see any difference when I slide the 'speed' setting from low to high or vice versa.
May be a duff sensor..
If you can't detect any difference between sensitivity settings, then there is something wrong.
For example, if they are working correctly, if they are a bit slow to react on the lowest setting for the rate of rain falling, will likely progress to be on continuously by the highest setting.
BTW, while running in auto mode do they ever go into continous mode, even the high speed wipe, if the rain is hard enough? They should do.
I had a Passat with auto wiper issues, erratic, sluggish, or not working when I thought they should, required a new sensor and then they were perfect.