Wiper Control Module: Description and Operation

Fig.10 Front Wiper Module:

FRONT WIPER MODULE
The front wiper module is secured with four screws through rubber isolators to the cowl plenum panel beneath the cowl plenum cover/grille panel. The ends of the wiper pivot shafts that protrude through dedicated openings in the cowl plenum cover/grille panel to drive the wiper arms and blades are the only visible components of the front wiper module. The front wiper module consists of the following major components:
- Bracket - The front wiper module bracket consists of a long tubular steel main member that has a stamped pivot bracket formation near each end where the two wiper pivots are secured. A stamped steel mounting plate for the wiper motor is secured with welds near the center of the main member.
- Crank Arm - The front wiper motor crank arm is a stamped steel unit with a slotted hole on the driven end that is secured to the wiper motor output shaft with a nut, and a ball stud secured to the drive end.
- Linkage - Two stamped steel drive links connect the wiper motor crank arm to the pivot lever arms. The passenger side drive link has a plastic socket-type bushing on each end. The driver side drive link has a plastic socket-type bushing on one end, and a plastic sleeve-type bushing on the other end. The socket-type bushing on one end of each drive link is snap-fit over the ball stud on the lever arm of its respective pivot. The driver side drive link sleeve-type bushing end is then fit over the motor crank arm ball stud, and the other socket-type bushing of the passenger side drive link is snap-fit over the exposed end of the wiper motor crank arm ball stud.
- Motor - The front wiper motor is secured with three screws to the motor mounting plate near the center of the wiper module bracket. The wiper motor output shaft passes through a hole in the module bracket, where a nut secures the wiper motor crank arm to the motor output shaft. The two-speed permanent magnet wiper motor features an integral transmission, an internal park switch, and an internal automatic resetting circuit breaker.
- Pivots - The two front wiper pivots are secured to the ends of the wiper module bracket. The crank arms that extend from the bottom of the pivot shafts each have a ball stud on their end. The upper end of each pivot shaft where the wiper arms will be fastened each has an externally serrated drum with a threaded stud secured to it.

The front wiper module cannot be adjusted or repaired. If any component of the module is faulty or damaged, the entire front wiper module unit must be replaced. The reinforcement bracket and stud plate are available for service replacement

The front wiper module operation is controlled by the battery current inputs received by the wiper motor from the wiper ON/OFF and wiper high/low relays. The wiper motor speed is controlled by current flow to either the low speed or the high speed set of brushes. The park switch is a single pole, single throw, momentary switch within the wiper motor that is mechanically actuated by the wiper motor transmission components. The park switch alternately closes the wiper park switch sense circuit to ground or to battery current, depending upon the position of the wipers on the glass. This feature allows the motor to complete its current wipe cycle after the wiper system has been turned OFF, and to park the wiper blades in the lowest portion of the wipe pattern. The automatic resetting circuit breaker protects the motor from overloads. The wiper motor crank arm, the two wiper linkage members, and the two wiper pivots mechanically convert the rotary output of the wiper motor to the back and forth wiping motion of the wiper arms and blades on the glass.

Fig.12 Rear Wiper Module:

REAR WIPER MODULE
The rear wiper module is concealed within the liftgate, below the liftgate glass and behind the liftgate trim panel. The end of the motor output shaft that protrudes through the liftgate outer panel to drive the rear wiper arm and blade is the only visible component of the rear wiper module. A rubber gasket, a bezel, and a nut seal and secure the motor output shaft to the liftgate outer panel. A molded plastic nut cover snaps onto the bezel to conceal the nut and improve appearance. The rear wiper module consists of the following major components:
- Bracket - The rear wiper module bracket consists of a stamped steel mounting plate for the wiper motor that is secured with screws to the wiper motor and to the liftgate inner panel.
- Electronic Controls - The rear wiper module electronic controls include the rear wiper system electronic logic and rear wiper motor electronic controls. The electronic controls for the motor include an electronic speed control that speeds the wiper blade near the center of the glass, but slows the wiper blade during directional reversals at each end of the wipe pattern and during wiper blade off-the-glass parking for quieter operation.
- Motor - The permanent magnet rear wiper motor is secured with screws to the rear wiper mod-ule bracket. The wiper motor includes an integral transmission, and the motor output shaft.

The rear wiper module cannot be adjusted or repaired. If any component of the module is faulty or damaged, the entire rear wiper module unit must be replaced. The motor output shaft gasket, bezel, nut, and nut cover are available for service replacement.

The rear wiper module receives non-switched battery current through a fuse in the Junction Block (JB) and is grounded at all times. The rear wiper module operation is controlled by the vehicle operator through battery current signal inputs received by the rear wiper module electronic controls from the right multi-function switch on the steering column. The module also receives an external control input from the liftgate flip-up glass ajar switch circuit. The rear wiper module electronic control logic uses these inputs, its internal inputs, and its programming to provide continuous wipe, delay wipe, wipe-after-wash and off-the-glass wiper blade parking. The wiper blade cycling is controlled by the rear wiper module electronic controls, which control current flow to the wiper motor brushes. The wiper motor transmission converts the rotary output of the wiper motor to the back and forth wiping motion of the rear wiper arm and blade on the liftgate glass.