GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2000 🢒 Savana 🢒 HVAC 🢒 HVAC Systems - Manual 🢒 Blower Motor Inoperative at Any Speed

Step

Action

Value(s)

Yes

No

DEFINITION: The front blower motor does not operate in any speed.

1

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

--

Go to Step 2

Go to Symptoms in HVAC Systems-Manual

2
  1. Place the ignition switch in the RUN position.
  2. Place the heater and A/C controller mode switch in the Heat position.
  3. Place the heater and A/C controller blower motor switch in the following positions:
    4. • HI
    • Medium-1
    • Medium-2
    • LO

Does the blower motor operate?

--

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

Go to Step 3

3
  1. Place the heater and A/C controller blower motor switch in the HI position.
  2. Disconnect the blower motor resistor/relay connector.
  3. Connect an J 35616-200 unpowered test lamp between the blower motor resistor/relay connector cavity B for CKT 52 (ORN) and ground. Refer to Circuit Testing in Wiring Systems.

Does the test lamp illuminate?

--

Go to Step 4

Go to Step 7

4

Connect a J 35616-200 unpowered test lamp between the blower motor resistor/relay connector cavity C for CKT 150 (BLK) and B+.

Refer to Circuit Testing in Wiring Systems.

Does the test lamp illuminate?

--

Go to Step 5

Go to Step 10

5
  1. Disconnect the blower motor connector.
  2. Connect a J 39200 digital multimeter (DMM) between blower motor resistor/relay pin F and blower motor connector cavity B for CKT 65 (PPL). Refer to Circuit Testing in Wiring Systems.

Is continuity present?

--

Go to Step 6

Go to Step 13

6

Connect a J 39200 DMM between blower motor resistor/relay pin C and blower motor connector cavity A, for CKT 150 (BLK).

Refer to Circuit Testing in Wiring Systems.

Is continuity present?

--

Go to Step 14

Go to Step 13

7
  1. Disconnect the heater and A/C controller C1 connector.
  2. Connect an J 35616-200 unpowered test lamp between the heater and A/C controller pin A and ground. Refer to Circuit Testing in Wiring Systems.

Does the test lamp illuminate?

--

Go to Step 8

Go to Step 9

8
  1. Disconnect the heater and A/C controller C2 connector.
  2. Connect a J 39200 DMM between heater and A/C controller connector C1 cavity A and connector C2 cavity G for CKT 119 (WHT). Refer to Circuit Testing in Wiring Systems.

Is continuity present?

--

Go to Step 15

Go to Step 11

9
  1. Disconnect the heater and A/C controller C2 connector.
  2. Connect an J 35616-200 unpowered test lamp between heater and A/C controller connector C2 cavity E for CKT 141 (BRN) and ground. Refer to Circuit Testing in Wiring Systems.

Does the test lamp illuminate?

--

Go to Step 15

Go to Step 12

10

Repair the open in CKT 150 (BLK) between the blower motor resistor/relay and ground G103.

Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 16

--

11

Repair the open in CKT 119 (WHT) between heater and A/C controller connector C1 and connector C2.

Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 16

--

12

Repair the open in CKT 141 (BRN) between the IP fuse block and heater and A/C controller connector C2.

Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 16

--

13

Replace the blower motor resistor/relay. Refer to Auxiliary Blower Motor Resistor Replacement .

Did you complete the repair?

--

Go to Step 16

--

14

Replace the blower motor. Refer to Blower Motor and Fan Replacement .

Did you complete the repair?

--

Go to Step 16

--

15

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

Did you complete the repair?

--

Go to Step 16

--

16

Operate the blower motor in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 3