Wiper and Washer Systems: Description and Operation

WIPER

When the Wiper/Washer Switch is in LO, battery voltage is supplied through the GRA wire directly to the low speed brushes of the Wiper Motor. The Wiper Motor runs at low speed.

When the Wiper/Washer Switch is in HI, battery voltage is applied through the PPL wire to the high speed brushes of the Wiper Motor. The motor operates at a higher speed.

The Park Switch is open only when the wiper blades are in the PARK position. In all other positions, the Park Switch is closed. When the Wiper/Washer Switch is moved to OFF, battery voltage at the WHT (93) wire is applied through the Park Switch, the Wiper/Washer Switch and the GRA (91) wire to the low speed brushes of the Wiper Motor. The Wiper Motor continues to run at low speed until the wiper blades reach the PARK position. At that time, the Park Switch opens and stops the Wiper Motor.

The pulse-type Wiper/Washer system includes an operating mode in which the wipers make single strokes with an adjustable time interval between strokes. The time interval is controlled by a Solid-State Pulse/Speed/Wash Control in the Wiper Motor Module. The duration of the relay interval is determined by the Delay Resistance in the Wiper/Washer Switch.

LOW SPEED

In the LO position, the Wiper/Washer Switch supplied voltage to the GRA (91) wire and the Pulse/Speed/Washer Control. The Pulse/Speed/Washer Control provides ground to the Park/Run Relay which is energized and supplies voltage to the brushes of the Wiper Motor. The wipers run at low speed until they are turned off.

HIGH SPEED

With the Wiper/Washer Switch in the HI position, battery voltage is supplied from the PPL (92) wire directly to a second armature terminal of the Wiper Motor. The wipers run at high speed. When the Wiper/Washer Switch is turned to OFF, the wipers complete the last sweep at low speed and park.

PARK

When the sipers are turned off, the Wiper Motor runs at low speed until the wiper blades reach the PARK position. At the time, the Park/Run Relay opens stopping the Wiper Motor immediately. The wiper blades remain in the PARK position.

MIST

When the control is moved to MIST and released, the wipers make one sweep at low speed and return to PARK. The circuit operation is the same as Low Speed.

PULSE

With the Wiper/Washer Switch in PULSE, voltage is applied to the GRA (91) wire, the Wiper Motor Module and the Solid-State Control Board. Voltage is supplied to the Park/Run Relay coil, which is momentarily grounded by the Pulse/Speed/Washer Control circuit, and the relay closes. Battery voltage is supplied by the WHT (93) wire through the closed contacts of the relay to run the Wiper Motor at LO speed. the relay remains energized as long as the contacts of the Park/Run Switch remain closed. Park/Run Switch opens, de-energizing the Park/Run Relay. The wiper blades remain in PARK until the Control Board grounds the Park/Relay coil to start another sweep. The delay time between sweeps is controlled by the pulse delay resistors. The delay can be adjusted from 0 to 43 seconds.

WASHER

When the Washer Switch is depressed, voltage is supplied to the Solid-State Control Board. The Control Board supplies battery voltage to the Washer Motor through the ORN (98) wire, Wiper Switch and PNK (94) wire. It also starts the wiper cycle through the low speed brushes of the Wiper Motor. The washer continues to run as long as the switch is held down. The Solid-State Control Board keeps the wipers on for approximately six switched on during the PULSE operation, the wipers run in low speed for six seconds. When the wash cycle is completed the wipers return to the PULSE operation.