Rain Sensing Wipers

[DaveMires]

Hello everyone, I know this has been asked many times before on the post, but my syptoms seem to be a little different, and to top it off I am in Seattle, where it seems like it never stops raining!

turn on wipers......wipe once and stop as they should, but then will wipe
again in around 10 seconds, does not change with
speed or with rain.

adjust frequency...wipers do not wipe, and this does not seem to change
frequency of random wipes.

sometimes they will work as they should and sense rain, and adjust speed to amount of water on windscreen, but if I adjust the frequency dial, they will stop working again...odd symptom. I am tempted to change out the sensor, as the windscreen is in great shape and hate to change it for this problem....any suggestions?

Thanks in advance.