You can try the resoldering of the control box, but apparently that is only applicable to the 84-91 trucks. I guess in 92 the control box was moved to the passenger side so the vibrations caused by the parking brake would not affect it. Another trick I have heard of is to remove the plastic cover on the wiper motor. You will find 3 metal strips on it, with nubs that wear down. Rebend them so they make better contant with the rings on the motor.