I have a 91 HDJ81, and the wipers have moved slowly since purchase. It has fresh blades, the wiper motor has just been replaced. With wiper arms detached, the motor sounds normal and speed varies with switch input as expected. With wiper arms on, it moves at a crawl. I replaced the motor initially because i suspected it was just weak. Has anyone else encountered this? Any ideas on how to get the wipers moving fast enough to see in the rain?