Nissan Maxima Service and Repair Manual: Blower motor

Description

COMPONENT DESCRIPTION

Brush-less Motor

The blower motor utilizes a brush-less motor with a rotating magnet.

Quietness is improved over previous motors where the brush was the point of contact and the coil rotated.

Blower Motor Circuit

Component Function Check

1.CHECK OPERATION

1. Warm up the engine.
2. Operate the fan control dial. Check that the fan speed and indicator are switched for all fan speeds.

Diagnosis Procedure

1.CHECK WITH SELF-DIAGNOSIS FUNCTION OF CONSULT

1. Using CONSULT, perform "SELF-DIAGNOSIS RESULTS" of HVAC.
2. Check if any DTC No. is displayed in the self-diagnosis results.

NOTE: If DTC is displayed along with DTC U1000 or U1010, first diagnose the DTC U1000 or U1010.

2.CHECK WITH ACTIVE TEST OF CONSULT

1. Using CONSULT, perform "HVAC TEST""ACTIVE TEST" of HVAC to check each output device. Refer to HAC-26, "CONSULT Function". NOTE: Perform the ACTIVE TEST after starting the engine because the compressor is operating.
2. Check that the blower motor control signal changes according to each indicator signal.

NOTE: Perform the inspection of each output device after starting the engine because the compressor is operating.

3.CHECK FUSE

Check 15A fuses (Nos. 21 and 22).

4.CHECK POWER SUPPLY FOR BLOWER MOTOR

1. Turn ignition switch OFF.
2. Disconnect blower motor connector.
3. Turn ignition switch ON.
4. Check voltage between blower motor harness connector M31 terminal 4 and ground.

4 - Ground: Battery voltage

5.CHECK BLOWER MOTOR GROUND CIRCUIT

1. Turn ignition switch OFF.
2. Check continuity between blower motor harness connector M31 terminal 1 and ground.

1 - Ground: Continuity should exist.

6.CHECK BLOWER MOTOR CIRCUIT CONTINUITY

1. Disconnect A/C auto amp. connector.
2. Check continuity between blower motor harness connector M31 (A) terminal 3 and A/C auto amp. harness connector M37 (B) terminal 32.

3 - 32: Continuity should exist.

7.CHECK A/C AUTO AMP. OUTPUT SIGNAL

1. Reconnect blower motor connector and A/C auto amp. connector.
2. Turn ignition switch ON.
3. Set MODE switch to the VENT position.
4. Check the output waveform between blower motor harness connector M31 terminal 3 and ground using an oscilloscope, while varying the fan speed from 1 to 7.

8.REPLACE FUSES

1. Replace fuses.
2. Activate the blower motor.

9.CHECK BLOWER MOTOR POWER SUPPLY CIRCUIT FOR SHORT

1. Turn ignition switch OFF.
2. Disconnect blower motor harness connector.
3. Check continuity between blower motor harness connector M31 terminal 4 and ground.

4 - Ground: Continuity should not exist.

10.CHECK POWER SUPPLY OF THE FRONT BLOWER MOTOR RELAY

1. Turn the ignition switch OFF.
2. Remove the front blower motor relay.
3. Turn the ignition switch ON.
4. Check the voltage between front blower motor relay harness connector J-4 terminals 2, 3 and ground.

2, 3 - Ground: Battery voltage

11.CHECK FRONT BLOWER MOTOR RELAY GROUND CIRCUIT

1. Turn ignition switch OFF.
2. Check continuity between front blower motor relay harness connector J-4 terminal 1 and ground.

1 - Ground: Continuity should exist.

12.CHECK BLOWER MOTOR SUPPLY CIRCUIT FOR OPEN

Check continuity between blower motor harness connector M31 terminal 4 and front blower motor relay harness connector J-4 terminal 5.

5 - 4: Continuity should exist.