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CH23 electrical accessories STUDENT VERSION rev

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Tài liệu học tập cơ bản khái quát về động cơ và các bộ phận trên ô tô phiên bản tiếng anh. Tài liệu này nhằm giúp chúng ta tiếp cận được cấu tạo chức năng của các bộ phận của xe. Với tài liệu này giúp các bạn sinh viên ngành cơ khí ô tô tiếp cận được những kiến thức cơ bản về ô tô và đồng thời nâng cao kiến thức tiếng anh. Bộ tài liệu này được soạn thảo bởi trường đào tạo và huấn luyện nghề ở Canada.

Chapter 23 Electrical Accessories Windshield Wiper/Washer Systems • Permanent magnet wiper circuits – Are the most common design – Speed is controlled by the placement of the brushes on the commutator – Three brushes are used – Park switch supplies voltage to motor after the wiper switch is turned off Windshield Wiper Systems (cont’d) • Electromagnetic field wiper circuits – Use two fields that are wired in opposite directions - the shunt field and the series field – A ground side switch determines the path of current flow and motor speed – The shunt field reduces motor speed – In high speed the shunt field ground has resistance, reducing current flow Windshield Washers • Most washer systems use a small electric pump installed in the fluid reservoir • A few pump styles operate off of the wiper motor • Some vehicles have washers that clean the headlights Common Wiper Concerns • • • • • Poor wiping No operation Intermittent operation Continuous operation Wipers will not park Horn Circuits • • • • • Horn Horn switch Slip ring Clockspring Horn relay Cruise Control Systems • Vacuum Systems – Was the most common system – A transducer senses and controls speed – The servo unit controlled the throttle based on vacuum input from transducer – Had an electrical and vacuum brake-activated switch to disconnect cruise control Cruise Control Systems (cont’d) • Electronic Systems – Use a control module to move a servo or stepper motor – Throttle-by-wire engines not use separate cruise control module – Cruise system uses VSS and brake position sensor inputs Diagnosis • Determine if whole system or part is not working • Use the system wiring schematic to determine the proper diagnostic procedure • Test the circuit breaker for the presence of voltage on both sides • Use a jumper wire to test the motor • Use a voltmeter to check the switches Power Seat Types • Two-way – Moves the seat forward and backward • Four-way – Moves the seat forward, backward, up, and down • Six-way – Moves the seat forward, backward, up, down, front tilt, and rear tilt Diagnosis • Visually inspect wires and connections • Test for available voltage at the switch • Use a continuity chart, if available, to check the switch • If the switch tests good, test the motors • Unusual noises can be caused by the motor, transmission, or cables Power Seat Circuit Power Mirror System • A “joystick” allows control of both mirrors from one switch • Dual motor drive assemblies are located in each mirror assembly • Some systems automatically adjust for parking maneuvers Rear-Window Defroster and Heated Mirror Systems • Rear-window defroster heats surface – Circuit has a switch, relay, and heating element Diagnosis • Common problem is damage to defroster grid • When a segment of the grid is damaged, the circuit opens • This leaves sections unheated Other Accessories • Adjustable pedals – Electric motor moves both pedals up to about three inches – May be part of memory seat function • Heated windshield – Uses a micro-thin coating within laminate – Directs generator output to windshield Other Accessories (cont’d) • • • • Moon (sun) roof Retractable hardtops Night vision iDrive – Used to control climate, entertainment, and all active driving control functions Security and Anti-Theft Systems • Pass-Key System – Uses a special resistance or transponder key • Keyless Entry System – May use a keypad mounted on the door or a remote key fob • Smart Keys – Can lock/unlock doors, allow engine start Alarm Systems • Can be active or passive • Passive systems switch on automatically • Active systems are activated with remote, keypad, key, or switch • If a switch is activated the alarm sounds • Can prevent the engine from starting ... controls speed – The servo unit controlled the throttle based on vacuum input from transducer – Had an electrical and vacuum brake-activated switch to disconnect cruise control Cruise Control Systems... for proper mounting • Always use the manufacturer’s diagnostic procedures Power Lock Systems • Reversible motors • Power and ground supplied through the switch • May automatically lock doors... Individual window drive motors Express-down module Lock-out or disable switch Circuit Operation • Reversible motors operate when power and ground are applied • Express windows use a module to control

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