Blower Motor Inoperative at Any Speed. Isuzu S/T Isuzu

For 1990-2009 cars only

Makes 🢒 Isuzu 🢒 2000 🢒 S/T Isuzu - 2WD 🢒 HVAC 🢒 Heating, Ventilation and Air Conditioning 🢒 Blower Motor Inoperative at Any Speed

Step

Action

Value(s)

Yes

Did you review the HVAC system operation and perform the necessary inspections?

Go to Step 2

Go to Symptoms

Verify that the blower motor is inoperative at any speed.

Does the blower motor operate normally?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

Disconnect the blower motor resistor.
Connect a test lamp between CKT 64 (BRN) wire and ground.
Turn ON the ignition.
Turn OFF the engine.
Cycle the mode selector between MAX and DEF.

Did the test lamp light in all of the mode switch positions?

Go to Step 6

Go to Step 4

Did the test lamp light in some of the mode switch positions?

Go to Step 5

Go to Step 17

Replace the heater and A/C controller. Refer to Control Assembly Replacement .

Is the replacement complete?

Go to Step 38

Connect a fused jumper between CKT 64 (BRN) and CKT 101 (DK BLU) in the blower motor resistor connector.

Does the blower motor operate?

Go to Step 7

Go to Step 8

Replace the blower motor resistor. Refer to Blower Motor Resistor Replacement in Heating, Ventilation and Air Conditioning.

Is the replacement complete?

Go to Step 38

Reconnect the blower motor resistor.
Disconnect the blower motor relay.
Connect a test lamp between CKT 101 (DK BLU) and ground.

Did the test lamp light?

Go to Step 10

Go to Step 9

Repair the open in CKT 101 (DK BLU).

Is the wire repair complete?

Go to Step 38

Use the J 35616-A in order to connect a fused jumper between CKT 101 (DK BLU) and CKT 65 (PPL).

Does the blower motor operate?

Go to Step 11

Go to Step 12

Replace the blower motor relay.

Is the replacement complete?

Go to Step 38

Disconnect the blower motor.
Connect a test lamp between CKT 65 (PPL) at the blower motor and ground.

Did the test lamp light?

Go to Step 14

Go to Step 13

Repair the open in CKT 65 (PPL).

Is the wire repair complete?

Go to Step 38

Connect a self-powered test lamp between CKT 850 (BLK) and ground.

Did the test lamp light?

Go to Step 16

Go to Step 15

Repair the open in CKT 850 (BLK) wire.

Is the wire repair complete?

Go to Step 38

Replace the blower motor. Refer to Blower Motor and Fan Replacement in Heating, Ventilation and Air Conditioning.

Is the replacement complete?

Go to Step 38

Inspect fuse 9.

Is fuse 9 open?

Go to Step 23

Go to Step 18

Connect a test lamp between CKT 141 (BRN) cavity C of the heater and the A/C controller connector C1 and ground.

Did the test lamp light?

Go to Step 20

Go to Step 19

Repair the open in CKT 141 (BRN).

Is the repair complete?

Go to Step 38

Connect a test lamp between CKT 64 (BRN) cavity B of the heater and the A/C controller connector C4 and ground.
Observe the test lamp, moving the mode selector switch from OFF to DEF.

Did the test lamp light in all of the mode switch positions?

Go to Step 22

Go to Step 21

Replace the heater and the A/C controller. Refer to Control Assembly Replacement .

Is the replacement complete?

Go to Step 38

Repair the open in CKT 64 (BRN) between cavity E of C3, cavity B of C4 and the blower motor resistor.

Is the wire repair complete?

Go to Step 38

Turn the ignition OFF.
Disconnect the heater and the A/C controller connectors.
Connect a self-powered test lamp between CKT 141 (BRN) cavity C of the heater and the A/C controller connector C2 and ground.

Did the test lamp light?

Go to Step 24

Go to Step 25

Repair the short to ground in CKT 141 (BRN).

Is the wire repair complete?

Go to Step 38

Disconnect the blower motor resistor.
Connect a self-powered test lamp between CKT 64 (BRN) cavity B of the heater and the A/C controller connector C4 and ground.

Did the test lamp light?

Go to Step 26

Go to Step 27

Repair the short to ground in CKT 64 (BRN) wire.

Is the wire repair complete?

Go to Step 38

Connect a self-powered test lamp between CKT 63 (TAN) wire cavity C of the heater and the A/C controller connector C3 and ground.

Did the test lamp light?

Go to Step 28

Go to Step 29

Repair the short to ground in CKT 63 (TAN).

Is the wire repair complete?

Go to Step 38

Connect a self-powered test lamp between CKT 72 (LT BLU) cavity B of the heater and the A/C controller connector C3 and ground.

Did the test lamp light?

Go to Step 30

Go to Step 31

Repair the short to ground in CKT 72 (LT BLU).

Is the wire repair complete?

Go to Step 38

Remove the blower motor relay.
Connect a self-powered test lamp between CKT 52 (ORN) wire cavity A of the heater and the A/C controller connector C3 and ground.

Did the test lamp light?

Go to Step 32

Go to Step 33

Repair the short to ground in CKT 52 (ORN).

Is the wire repair complete?

Go to Step 38

Reconnect the heater and the A/C controller.
Connect a self-powered test lamp to CKT 64 (BRN) at the blower motor resistance.

Did the test lamp light?

Go to Step 34

Go to Step 35

Replace the heater and the A/C controller. Refer to Control Assembly Replacement .

Is the replacement complete?

Go to Step 38

Connect a digital multimeter (DMM) between terminal 86 and 85 of the blower motor relay in order to measure the resistance of the relay.

Is the resistance less than the specified value?

0.5 ohms

Go to Step 36

Go to Step 37

Replace the blower motor relay.

Is the replacement complete?

Go to Step 38

Repair the intermittent shorts to ground in the following circuits:

1.1.	CKT 141 (BRN)

1.2.	CKT 64 (BRN)

1.3.	CKT 63 (TAN)

1.4.	CKT 72 (LT BLU)

1.5.	CKT 65 (PPL)

1.6.	CKT 52 (ORN)

Replace the blower motor if no short is found.

Is the wire repair complete?

Go to Step 38

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3