Power Supply And Ground Circuit For Auto Amp

POWER SUPPLY AND GROUND CIRCUIT FOR AUTO AMP.





Description

COMPONENT DESCRIPTION

Auto Amp. (Automatic Amplifier)





The auto amp. (1) has a built-in microcomputer which processes information sent from various sensors needed for air conditioner operation. The air mix door motors, mode door motor, intake door motor, blower motor and compressor are then controlled.
The auto amp. is unitized with control mechanisms. Signal from various switches and potentio temperature control (PTC) are directly entered into auto amp.

Power Supply and Ground Circuit for Auto Amp.

Potentio Temperature Control (PTC)





The PTC (1) is built into the auto amp. It can be set at an interval of1�C (2�F) in the 18�C (60�F) to 32�C (90�F) temperature range by turning temperature control dial. The set temperature is displayed.









Component Function Check
1.CONFIRM SYMPTOM BY PERFORMING THE FOLLOWING OPERATIONAL CHECK
1. Turn ignition switch ON (READY).
2. Press AUTO switch and A/C switch.
3. Each switch indicator will turn ON. Confirm that Discharge air and blower speed will depend on ambient, in-vehicle and set temperatures.
Is the inspection result normal?
YES - Inspection End.
NO - Go to Diagnosis Procedure. SEE Diagnosis Procedure.




Diagnosis Procedure
Regarding Wiring Diagram information, [1][2]Electrical Diagrams.
1.CHECK POWER SUPPLY CIRCUIT FOR AUTO AMP.
1. Disconnect auto amp. connector.
2. Check voltage between auto amp. harness connector M37 terminals 19, 39 and 40 and ground.





Is the inspection result normal?
YES - GO TO 3.
NO - GO TO 2.
2.CHECK FUSE
Check 10A fuses [Nos. 3, 6 and 19, located in the fuse block (J/B)]. Fuse Block - Junction Box (J/B).
Is the inspection result normal?
YES - Check harness for open circuit. Repair or replace if necessary.
NO - Check harness for short circuit and replace fuse.
3.CHECK GROUND CIRCUIT FOR AUTO AMP.
1. Turn ignition switch OFF.
2. Check continuity between auto amp. harness connector M37 terminal 17, 37 and ground.





Is the inspection result normal?
YES - Replace auto amp. Service and Repair.
NO - Repair harness or connector.