This weekend, I finally diagnosed a strange noise we'd been getting under the hood to the left headlight wiper motor, which is staying on but not moving the wiper. It operates only when the ignition is on, and then constantly.

I'm assuming that what's happening here is that the motor is stuck in the "run until you reach the rest position" mode. The short-term solution was to disconnect the plug (which Volvo fortunately put in a very accessible and intuitive location) and cover both parts of the connector with plastic baggies.

Any ideas about the longer-term solution, if any? Or is it motor replacement time?