Wiper and Washer Systems: Description and Operation

CIRCUIT OPERATION
The windshield wiper on this vehicle is unique due to the windshield design and the overlap of the wiper blades.

The wiper system consists of: driver and passenger wiper motors, a wiper feedback RPM signal for each wiper motor, wiper switch, and control module.

The wiper module controls all modes of operation, and also synchronizes the wiper blades so they do not make contact with each other.

Battery feed for the wiper motors and the wiper control module is supplied on circuit M1. This circuit is protected by a 20 Amp fuse in cavity 15 of the fuse block, and HOT at all times.

Power for fuse 15 is supplied on circuit A6. This circuit is protected by a fusible link located near the auxiliary jumper post on the left toe box.

A battery feed is supplied to the wiper control module on circuit V6. This circuit is HOT when the ignition switch is in the ACCESSORY or RUN position. Circuit V6 is protected by a 20 Amp fuse in cavity 18 of the fuse block. Power for the fuse is supplied by circuit A48 from the ignition switch.

For the wiper module to control the wiper motor's operation, it must sense the position of the wiper blades. The position is sensed through two switches built into each wiper motor that indicate when the motor is in the reversal (UP), or the park position (DOWN). After determining the switch positions, the module uses a motor speed signal to synchronize the wiper operation.

The synchronization process compensates for the speed difference between the motors. This prevents the wiper blades from contacting each other. To keep the motors synchronized, the module continues to use the motor position input.