first make sure ur wipers are tight on the splines... there shouldn't be any noticeable movement on the wiper arm and wiper shaft when u move it physically... if there is then tighten that frst.
IF THAT DOESN'T WORK:
disconnect battery overnight so u reset the PCM, body electronics,all the modules. reconnect in the morning an let's see what happens ;-)
(make sure u know your radio code-or your radio will not work when you reconnect)