Report "1998 gmc sierra windshield wipers don't always work in the rain. They seem to always work when it's not raining but only about 25% of the time when it is raining. I realize they had an issue (recall) with the circuit board on the motors on those models but on this truck I can hear the motor whine when I turn them on so I'm not sure if it is the motor. I believe it is but would like to know if anyone has experienced this before I buy a new motor"