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Home >> Toyota Truck >> 2005 >> Tacoma PreRunner L4-2.7L (2TR-FE) >> Repair and Diagnosis >> Heating and Air Conditioning >> Testing and Inspection >> Initial Inspection and Diagnostic Overview >> Component Inspection

Component Inspection

INSPECTION







1. INSPECT AIR CONDITIONING CONTROL ASSEMBLY
a. Check the blower switch resistance.
1. Using an ohmmeter, measure the resistance and check the results in accordance with the values in the table
If the result is not as specified, replace the air conditioning control assembly.







b. Check the temperature selector switch voltage.
1. Apply battery voltage (13.5V) across terminals 10 (IG) and 9 (GND).
2. Connect the positive (+) tester probe of a voltmeter to terminal 6 (AMSW) and the negative (-) tester probe to terminal 9 (GND), then check the voltage.
If the result is not as specified, replace the air conditioning control assembly.







c. Check the mode selector switch voltage.
1. Apply battery voltage (13.5V) across terminals 10 (IG) and 9 (GND).
2. Connect the positive (+) tester probe of a voltmeter to terminal 5 (MSET) and the negative (-) tester probe to terminal 9 (GND), then check the voltage.
If the result is not as specified, replace the air conditioning control assembly.




d. Inspect the illumination operation.
1. Connect the positive (+) lead from the battery to terminal 3 (ILL+) and negative (-) lead to terminal 8 (ILL-), then check that the illuminations light up.

Standard: Illuminations light up

If the result is not as specified, check the faulty bulb.




e. Inspect the bulb.
1. Inspect continuity of the bulb by connecting the tester as shown in the illustration.

Standard: 7 to 11 Ohms at 20 °C (68 °F)

If continuity exists, replace the heater control.
If no continuity exists, replace the bulb.




f. Inspect A/C indicator operation.
1. Connect the positive (+) lead from the battery to terminal 10 (IG) and negative (-) lead to terminal 2 (ACID) and 9 (GND).
2. Push the A/C button in and then check that the indicator lights up.

Standard: Indicator lights up
If the result is not as specified, replace the air conditioning control assembly.




3. Under the above condition, connect the positive (+) lead from the battery to terminal 3 (ILL+) and then check that the indicator dims.

Standard: indicator dims
If the result is not as specified, replace the air conditioning control assembly.




g. Inspect the REC indicator operation.
1. Connect the positive (+) lead from the battery to terminal 10 (IG) and negative (-) lead to terminal 4 (REC) and 9 (GND).
2. Push the REC button in and then check that the indicator lights up.

Standard: Indicator lights up
If the result is not as specified, replace the air conditioning control assembly.




3. Under the above condition, connect the positive (+) lead from the battery to terminal 3 (ILL+) and then check that the indicator dims.

Standard: Indicator dims
If the result is not as specified, replace the air conditioning control assembly.




2. INSPECT MAGNET CLUTCH ASSEMBLY
a. Inspect the magnet clutch assembly.
b. Confirm that the magnet clutch hub and magnet clutch rotor lock when the battery positive lead is connected to terminal 1 (MG+) of the magnet clutch, and the negative lead is connected to the earth wire.
If the operation is not as specified, replace the magnet clutch assembly.




3. INSPECT COMPRESSOR PICK UP SENSOR
a. Check the compressor pick up sensor voltage.
1. Connect the positive (+) lead from the battery to terminal 3 (SSR-) and the negative (-) lead to terminal 1 (MG+),and measure the voltage between terminals 1 (MG+) and 2 (SSR+).

Standard: 2.5 ± 0.5 V

2. When surface A of the compressor pick up sensor is close to the S-pole, the voltage between terminals 1 (MG+) and 2 (SSR+) increases. When it is close to the N-pole, the voltage between the terminals decreases.

If the result is not as specified, replace the compressor pick up sensor.




4. INSPECT AIR INLET CONTROL SERVOMOTOR
a. Inspect the servomotor operation.
1. Connect the positive (+) lead from the battery to terminal 1 (FRS) and negative (-) lead to terminals 2 (REC), then check that the shaft rotates clockwise smoothly.
2. Connect the positive (+) lead from the battery to terminal 2 (REC) and negative (-) lead to terminal 1 (FRS) then check that the shaft rotates counter clockwise smoothly.
If the operations are not as specified, replace the air control servomotor.




5. INSPECT MODE CONTROL SERVOMOTOR
a. Inspect the servomotor operation.
1. When 12V is applied between terminals 4 (IGN) and 1 (GND), and 0V is applied between terminals 2(SIG) and 1 (GND), check that the line connecting the 2 notches moves to the 0V position.
If the result is not as specified, replace the mode control servomotor.

2. When 12V is applied between terminals 4 (IGN) and 1 (GND), and 6V is applied between terminals 2 (SIG) and 1 (GND), check that the line connecting the 2 notches moves to the 6V position.
If the result is not as specified, replace the mode control servomotor.

3. When 12V is applied between terminals 4 (IGN) and 1 (GND), and between terminals 2 (SIG) and 1 (GND), check that the line connecting the 2 notches moves to the 12V position.
If the result is not as specified, replace the mode control servomotor.




6. INSPECT AIR MIX CONTROL SERVOMOTOR
a. Inspect the servomotor operation.
1. When 12V is applied between terminals 4 (IGN) and 1 (GND), and 0V is applied between terminals 2 (SIG) and 1 (GND), check that the line connecting the 2 notches moves to the 0V position. If the result is not as specified, replace the air mix control servomotor.
2. When 12V is applied between terminals 4 (IGN) and 1 (GND), and 6V is applied between terminals 2 (SIG) and 1 (GND), check that the line connecting the 2 notches moves to the 6V position.
If the result is not as specified, replace the air mix control servomotor.
3. When 12V is applied between terminals 4 (IGN) and 1 (GND), and between terminals 2 (SIG) and 1 (GND), check that the line connecting the 2 notches moves to the 12V position.
If the result is not as specified, replace the air mix control servomotor.




7. INSPECT BLOWER W/FAN MOTOR SUB-ASSEMBLY
a. Inspect the blower w/ fan motor.
1. Connect the positive (+) lead from to terminal 1 and negative (-) lead to terminal 2, then check that the motor operates smoothly.

CAUTION:
- Use safety glasses
- Do not use battery power, use DC power supply (30 A).
- Do not operate the motor and fan assembly at over 5V.
- Be sure to hold the motor in a stable and safe way.

If the result is not as specified, replace the blower w/fan motor.







8. INSPECT BLOWER RESISTOR
a. Check the resistance.
1. Using an ohmmeter, measure the resistance between the terminals.
If the result is not as specified, replace the blower resistor.







9. INSPECT COOLER THERMISTOR SENSOR
a. Check the resistance.
1. Measure the resistance and check the results in accordance with the values in the table.
If the result is not as specified, replace the cooler thermistor sensor.





NOTE:
- Even slightly touching the sensor may change the resistance value. Be sure to hold the connector of the sensor.
- When measuring, the sensor temperature must be almost the same as the ambient temperature.

HINT: As the temperature increases, the resistance decreases.







10. INSPECT MAGNET-CLUTCH RELAY
a. Check the resistance.
1. Using an ohmmeter, measure the resistance between the terminals.
If the result is not as specified, replace the relay.







11. INSPECT HEATER RELAY
a. Check the resistance.
1. Using an ohmmeter, measure the resistance between each terminal.
If the result is not as specified, replace the relay
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