Heater & Automatic Air Conditioning: Overhaul Nissan Juke I

A/C UNIT ASSEMBLY: Aspirator

The aspirator generates the vacuum by the air blown from the A/C unit assembly and draws the air of the passenger room to the in vehicle sensor area via the aspirator duct.

Scheme 87

A/C UNIT ASSEMBLY: Intake Sensor

Intake sensor measures temperature of evaporator fin temperature. The sensor uses a thermistor which is sensitive to the change in temperature. The electrical resistance of the thermistor decreases as temperature increases.

A/C UNIT ASSEMBLY: Air Mix Door Motor

1. The step motor system is adopted for air mix door motor.
2. When a drive signal is input from A/C auto amp. to door motor, a step motor built into the door motor rotates according to the drive signal, and then stops at the target door position. Refer to " «DOOR CONTROL»(ref-516424-S38640631472012120600000) ".
3. Rotation of motor is transmitted to air mix door (upper air mix door and lower air mix door) by lod and lever. Air flow temperature is switched.

A/C UNIT ASSEMBLY: Mode Door Motor

1. The step motor system is adopted for mode door motor.
2. When a drive signal is input from A/C auto amp. to door motor, a step motor built into the door motor rotates according to the drive signal, and then stops at the target door position. Refer to " «DOOR CONTROL»(ref-516424-S38640631472012120600000) ".
3. Rotation of motor is transmitted to mode door (center ventilator and defroster door, sub defroster door, side ventilator door, and foot door) by link, lod, and lever. Air outlet is switched.

A/C UNIT ASSEMBLY: Intake Door Motor

1. Intake door motor consists of motor that drives door and PBR (Potentio Balance Register) that detects door position.
2. Motor operates intake door according to control signal from A/C auto amp. Refer to " «DOOR CONTROL»(ref-516424-S38640631472012120600000) ".
3. Rotation of motor is transmitted to intake door by lever. Air inlet is switched.
4. PBR (Potentio Balance Register) transmits PBR feedback signal to A/C auto amp. according to motor position.
5. According to PBR feedback signal, A/C auto amp. monitors that motor is in an appropriate door position.

Scheme 88

Scheme 89

1. The blower motor utilizes a brush-less motor with a rotating magnet.
2. Quietness is improved over previous motors where the brush was the point of contact and the coil rotated.

Scheme 90

1. Power transistor, that uses MOS field effect transistor, is adopted for blower motor speed control. NOTE: MOS field effect transistor is a transistor for which the gate portion is composed of a metal electrode on an oxide layer of semiconductor. Field effect transistor is controlled by voltage, while ordinary transistor is controlled by current. Electrode of field effect transistor is called source, drain, or gate, while electrode of ordinary transistor is called emitter, collector, or base.
2. Power transistor continuously controls voltage to blower motor, according to gate voltage from A/C auto amp.
3. This power transistor does not require a HI relay even when the maximum voltage is applied to blower motor at HI status, because voltage drop is nominal.