Electric Engine-Cooling Fans

Electric engine-cooling fans are used on all transversely and some longitudinally mounted engines. Small, permanent-magnet, high-torque motors are used for this application. They are able to move large amounts of air independent of engine speed. Conventional electric cooling fan circuits incorporate a relay and engine-coolant temperature switch.When engine coolant temperature increases above 230*F or 100*C, the cooling fan switch closes to energize the relay coil and switch the cooling fan motor ON. The coil is also energized to switch the cooling fan motor ON any time the air conditioning unit is ON. On some vehicles the temperature-switch circuit is hot at all times, allowing the fan to continue to cool the engine compartment and the radiator coolant even if the ignition switch is OFF. For...

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Electronic Variable-Assist Power Steering

The power steering unit is designed to reduce the mount of effort required to turn the steering wheel. Conventional Power steering system operate by means of hydraulic pump driven by abelt from the crankshaft pulley. This pump provides the fluid pressure and flow needed to operate the system. Maximum pressure line and return line connect the pump to the system. the hydraulic pressure provides most of the force needed for steering. The remaining steering effort provides needed driver feel for googd steering control.The basic purpose of an electronic variable assist power steering system is to provide maximum power assist for light steering effort during low-speed vehicle maneuvering, such as parking, and minimum power assist for firm steering wheel control and directional stability at higher...

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Motor Blower of AC

An most cases, the blower motor moves air inside a vehicle for air conditioning, heating and defrosting. A blower switch(in dashboard) is used in conjunction swith resistor block to control fan speeds. The resistor block consists of two coil-wound wire resistors connected to terminals. These resistors drop the voltage and reduce the current to the motor, causing it to turn more slowly. The blower switchs directs current through one resistor to run the motor at low speed, through one resistor to run the motor at medium speed, and directly to the motor to run the motor at high speed.Some computer-controlled blower motor system have eliminated the blower motor resistors. Instead of varying current through the motor with resistors, the current...

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Oxygen (O2) Sensor

The exhaust gas or oxygen (O2) sensor is a device used by the vehicle's engine computer to measure the amount of oxygen present in the exhaust stream after combustion has taken place. This information is used by the computer to maintain the ideal air/fuel ratio.The heart of oxygen sensor is a hollow cone-shaped piece of ceramic material called zirconium dioxide that is platinum coated on the inside and outside. This platinum coating provides the electrodes, as in a battery. During engine operation, exhaust gases are forced to pass over the outside of the sensor element while the inside is exposed to outside air (also referred to as reference gas). When the amount of oxygen in the exhaust differs from the reference gas, a voltage is produced.A...

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Ignition Module And Coil Driver

An ignitions module houses integrated circuits that contai transistor, diodes, resistor and capacitor. A power within the module is used to switch primary current ON and OFF. It works much like a mechanical switch, except that it has no moving part and is turned ON and OFF by timed electrical pulses.Ignitions module uses a transistor to switch primary current ON and OFF Although many different type of ignition modules are used, they all perform basically the same function: switch primary current On and Off. That image Shows an ignitions module that uses a singgle transistor to control primary current to ignition coil of a distributor-type ignitions system.The image shows an ignition module that usesIGNITION COIL DRIVER POWER ICThe modern ignition...

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Car Ignition System Works

The ignition system in your car ignites the fuel inside the engine's combustion chamber at the optimal time in the piston stroke to produce the most power while emitting the least amount of emissions as possible. There are many configurations of ignition systems but all operate on the same principle, create a low energy field and collapse it onto a high energy coil and that transfers the electrical energy into the secondary ignition system, coil wire, distributor cap and rotor (if equipped) plug wires and finally the spark plug. Typical Ignition System in OperationThis system is triggered by the primary ignition system, this system varies depending on manufacturer but all operate on the same principle, use some kind of low voltage...

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Handling The ECU (Electronic Control Unit)

ECU (Electronic Control Unit) contains electronic component that are extremely sensitivy to power surges, static, electricity, and phisical shock. Whenever working on or around microcomputer-based system, the following procedures should be used to avoid damaged to electronic component.* Power must always be OFF wen removing or installing Ecu wiring harness connector. Make sure the ignitions is turned off and the ECu Fuse Removed.* To get rid of any static charge buildup, frequently touch a known good ground with your hands or use statistic protection kit during installation of a ECu. This is especially important if you are moving your feet on a carpet or sliding across a seat.* Jumper cable should be connected and disconnected with...

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