Principles of Operation

PRINCIPLES OF OPERATION

Windshield Wiper Operation
The multi-function switch controls the front wiper/washer portion and is wired to the smart junction box (SJB). When the switch is moved to the desired position, one or more of circuits CRW18 (VT/WH), CRW19 (BU/OG), CRW08 (VT/OG) or CRW17 (GN/VT) is grounded through circuit CD116 (BK/VT). This will provide the necessary inputs for the SJB to control the run/park relay and the hi/low relay (integral to the SJB) coils. In order to achieve high-speed operation, both relays are energized. The SJB will respond to the multi-function switch inputs only when the ignition lock cylinder is in RUN or ACC.

The SJB includes a speed dependent feature which compensates for the extra moisture that accumulates on the windshield at higher vehicle speeds when the multi-function switch is in any intermittent setting except the INT 1 position. As vehicle speed increases, the speed dependent feature gradually shortens the delay between wipes.

The speed dependent feature is easiest to verify in the INT 2 position. With the vehicle at a standstill and the multi-function switch in the INT 2 position, the wipers should operate once every 10 seconds. As vehicle speed increases, the delay between wipes will gradually shorten. For example, by the time the vehicle reaches 100 km/h (62 mph), the wipers should operate every 5 seconds. Speed dependent operation is similar in INT 3, INT 4 and INT 5 modes.

Windshield Washer System
The washer pump relay is hard-wired to the SJB. The washer switch portion of the multi-function switch will ground circuit CRW07 (GY/BN) which will signal the SJB to energize the washer pump relay (integral to the SJB). The relay will then provide voltage to the windshield washer pump through circuit CRW14 (BU/WH). The windshield washer pump is grounded through circuit GD123 (BK/GY).