GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1998 🢒 Lumina 🢒 HVAC 🢒 HVAC Systems - Manual 🢒 Blower Motor Always On

Step

Action

Value(s)

Yes

No

1
  1. Disconnect the blower motor resistor.
  2. Place the ignition switch in the RUN position.
  3. Place the heater - A/C control in the VENT position.
  4. Place the blower switch in the OFF position.
  5. Use a test lamp to backprobe between the following blower motor resistor harness connector terminals and ground:
    6. • LO -D
    • M1 - B
    • M2 - A

Does the test lamp light?

--

Go to Step 2

Go to Step 5

2
  1. Keep the probe connected to the same terminal that turned the test light on.
  2. Disconnect the heater - A/C control connector C 1.

Did the test lamp light?

--

Go to Step 3

Go to Step 4

3

Locate and repair a short to B+ in the affected circuit:

    • LO - Blower motor resistors harness connector terminal D circuit 60 (YEL).
    • M1 - Blower motor resistors harness connector terminal B circuit 63 (TAN).
    • M2 - Blower motor resistors harness connector terminal A circuit 72 (LT BLU).

Is the repair complete?

--

Go to HVAC Blower Controls System Check

--

4

Replace the heater - A/C control. Refer to Control Assembly Replacement .

Is the repair complete?

--

Go to HVAC Blower Controls System Check

--

5
  1. Place the ignition switch in the OFF position.
  2. Disconnect the blower motor relay.
  3. Place the ignition switch in the ON position.
  4. Use a test lamp to backprobe between the blower motor relay harness connector terminal C 2 circuit 52 (ORN) and ground.

Does the test lamp light?

--

Go to Step 6

Go to Step 8

6
  1. Place the ignition switch in the OFF position.
  2. Disconnect the heater - A/C control connector C 1.
  3. Place the ignition switch in the ON position.
  4. Use a test lamp to backprobe between blower motor relay harness connector terminal C 2 and ground.

Does the test lamp light?

--

Go to Step 4

Go to Step 7

7

Locate and repair the short to B+ in circuit 52(ORN).

Is the repair complete?

--

Go to HVAC Blower Controls System Check

--

8
  1. Place the ignition switch in the OFF position.
  2. Connect the blower motor resistor connector.
  3. Place the ignition switch in the ON position.
  4. Use a test lamp to probe between the blower motor relay harness connector terminal B 2 and ground.

Does the test lamp light?

--

Go to Step 9

Go to Step 12

9
  1. Turn the ignition switch to the OFF position.
  2. Disconnect the blower motor resistor.
  3. Turn the ignition switch to the ON position.
  4. Use a test lamp to backprobe between the blower motor relay harness connector terminal B 2 and ground.

Does the test lamp light?

--

Go to Step 10

Go to Step 11

10

Locate and repair the short to B+ in circuit 101 (DK BLU).

Is the repair complete?

--

Go to HVAC Blower Controls System Check

--

11

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

Is the repair complete?

--

Go to HVAC Blower Controls System Check

--

12

Use a test lamp to backprobe between the blower motor relay harness connector terminal C 1 and ground.

Does the test lamp light?

--

Go to Step 13

Go to Step 14

13

Locate and repair a short to B+ in CKT 65 (PPL).

Is the repair complete?

--

Go to HVAC Blower Controls System Check

--

14

Replace the blower motor relay.

Is the repair complete?

--

Go to HVAC Blower Controls System Check

--