GM Service Manual Online
For 1990-2009 cars only

The wiper motor receives battery voltage at terminals B and C through CKTs 391/393 and 1240 during high and low speed operation. CKT 1240 is hot at all times. Battery voltage in CKT 391/393 goes through the wiper cutout switch before reaching the wiper motor, therefore, the switch must be closed for wiper operation.

The wiper motor is grounded at terminal A through CKT 1350.

The wiper motor receives battery voltage at terminal D through CKT 392 when the wiper switch is pushed to WASH. The washer pump also receives battery voltagge through CKT 392 at terminal A of the washer pump connector. The washer pump operates only as long as the wiper switch is held in the WASH position and is grounded through CKT 350.