I have a 2000 BMW 528i E39 with rain sensing wipers. When I turn the wipers on in rain sensing mode the wipers intermittently wipe every 8 seconds weather it is raining or not. I replaced the relay but this did not help. They had been working perfectly so I know it is not user error. The windshield has not been replaced nor have any modifications been made to the vehicle since it has quit working. Has anyone seen this issue?