Wiper and Washer Systems: Description and Operation
GENERAL INFORMATIONWindshield Wiper System
An intermittent windshield wiper system is standard equipment on this model. The intermittent wiper system lets the driver select from either of two wiper speeds, low or high, or the intermittent wipe delay mode. A knob on the end of the multi-function switch stalk is rotated to select the desired wiper speed, or the intermittent wipe delay mode and interval.
On models equipped with a base version of the Central Timer Module (CTM), the intermittent wipe mode delay times are driver adjustable from about one-half second to about eighteen seconds. On models equipped with a high-line version of the CTM, the intermittent wipe mode delay times are speed sensitive. Above about sixteen kilometers-per-hour (ten miles-per-hour) the delay is driver adjustable from about one-half second to about eighteen seconds. Below about sixteen kilometers-per-hour (ten miles- per-hour) the high-line CTM doubles the delay time, or provides delays of about one second to about thirty-six seconds. The intermittent wipe mode is provided by delay logic and relay control circuitry contained within the CTM, and an intermittent wipe relay.
The windshield wipers will operate only when the ignition switch is in the Accessory or On positions. A fuse located in the junction block protects the circuitry of the windshield wiper system.
SPEED SENSITIVE INTERMITTENT WIPERS
The AN truck equipped with a highline CTM will utilize speed sensitive intermittent wipers. Only a highline CTM will be able to support this feature. A base CTM will provide for intermittent wipers without the speed sensitive feature. The low and high speeds are controlled through the wiper stalk switch. The intermittent portion of the wiper control is handled by the CTM through the intermittent wiper relay. When the module detects a decrease in delay time as selected by the driver, an immediate wipe of the windshield takes place and the new delay interval is implemented.
Following are general descriptions of the major components in the windshield wiper system. Refer to the owner's manual in the vehicle glove box for more information on the features, use and operation of the windshield wiper system.
Windshield Washer System
An electrically operated windshield washer system is standard equipment. A knob on the end of the multi-function switch stalk is depressed toward the steering column to activate the washer system. A washer reservoir in the engine compartment holds the washer fluid, which is pressurized by a pump when the windshield washer switch is actuated. The windshield washer pump feeds the pressurized washer fluid through the washer system plumbing to the windshield washer nozzles.
A standard equipment low washer fluid warning lamp in the instrument cluster will warn the driver when the washer fluid level needs to be checked.
The washers will operate only when the ignition switch is in the Accessory or On positions. A fuse located in the junction block protects the circuitry of the washer system.
Refer to the owner's manual in the vehicle glove box for more information on the features, use and operation of the windshield washer system.