Chery A21 2005 Service Manual page 273

Auto A/C System Circuit Analyse：
The Auto A/C is shown as figure12-1. When the ignition switch is at the position of ON, the
ACC1 and the 15th wire gets electricity.
The 15th line supplies power to the B1 pin of A/C controller via Fb7 fuse; the
B2 B9 B10 B16 、 、 、 pin of A/C controller connect to ground.
The voltage of A CC1 wire supplies power to the 5th pin of blower speed adjusting module
via the Fb13 fuse; the 7th、8th pin of blower adjusting module is connected to the blower motor;
the 6th pin connects to ground; the 3rd pin is the blower speed adjusting signal, and connects to the
A5 pin of A/C controller; the 2nd pin is the blower voltage feedback signal, and connects to the A4
pin of A/C controller.
The B5、B6 pin of A/C controller connect to inner/outer circulation control motor, the
control panel drives the circulate wind door connecting pole、 move pole by the control of
inner/outer circulation servor motor , and also move the big、 small wind door and thereby it
realize the control of inner/outer circulate wind.
The B7、B8 pin of A/C controller connect to the cool/warm control motor, the control
pa nel drives the dial and the pole in the temperature adjusting unit by controlling the blend door
servor motor, and also move the blend door and thereby it realized the different proportional air
mixture.
The B3、B4 pin of A/C c ontroller connect to the mode control motor, the control panel
drives the dial and the pole in the wind direction adjusting unit by controlling the mode wind door
servor motor, different pole control the open and close of different wind door and thereby it realizes
the control of air.
The A18 pin of A/C controller connects the outer temperature sensor. The outer
temperature sensor is one of the important sensor of auto A/C. It will influence the air temperature
of the wind outlet port、wind volume of the wind outlet port、the position of mode door and the
po sition of air intake port. For the inspection of outer temperature, you can dismantle the
connector of the sensor and test the DC voltage of the the front ground/front engine
compartment/D end o f the wiring harness, the normal value is 5V, if not, that's to say there is
something wrong with the wiring harness or A/C computer.
The A15 pin of A/C controller connects the inner temperature sensor. The inner
temperature sensor is one of the important sensors of auto A/C.It will influence the air temperature
of the wind outlet port、wind volume of the wind outlet port、the position of mode door and the
po sition of air intake port. For the inspection of inner temperature, you can dismantle the
connector of the sensor and test the DC voltage of the two ends of the wiring harnes s, the normal
value is 5V, if not, that's to say there is something wrong with the wiring harness or A/C computer.
The A14 pin of the A/C controller connects to the coolant temperature sensor. The coolant
temperature sensor is to test the temperature of heater core and modify the position of the blend door.
It can avoid the working of compressor when the engine is in high temperature; it can also
control the blower, when the coolant temperature is too low, the system will start the preheat
control. That's to say when the coolant temperature is too low and it is in warming working
condition , to prevent the cool wind from blowing out, if the coolant temperature is lower than the
system set temperature, the blower will work in low speed or doesn't work.
The A19 pin of A/C controller connects to sunshine sensor. The sunshine sensor induce the
A18 、 A2 、
the strong or weak of the sunshine to modify the position of blend door and speed of blower. To
inspect the sunshine sensor, you can read fault code or in the way of testing the resistance or voltage.
（1）Te st the resistance
Test in strong su nshine, th e resistan ce will be 4kΩ , co ver the s unshine s ensor, the
resist ance will be ∞.
（2）Te st the vol tage
The volta ge in stro ng sunshin e is norm ally lower than 1V, cover the sunshine s ensor, the
volta ge will be over 4V.
B 7 B8 A17
W
V /B V/W
TO
lower S peed
Control M odule
3 6 2
1
5
Tem perature Co ntro l
Motor
Te mpera tur e Cont rol Motor
Air Conditio ner Contr oller
B4 B3
L
L/B
6
1 3
Mod e Co ntro l
Moto r
Mode Cont rol Motor
A1 A16 A11
L/W
V/Y V/R
2
5
25