GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1998 🢒 Safari - 4WD 🢒 HVAC 🢒 HVAC Systems - Manual 🢒 Blower Motor Inoperative at Any Speed

Step

Action

Value(s)

Yes

No

1

Did you perform the HVAC Blower Controls System Check?

--

Go to Step 2

Go to HVAC Blower Controls System Check

2

Inspect the HTR-A/C fuse 12 at the IP fuse block.

Is the fuse operational?

--

Go to Step 4

Go to Step 3

3
  1. Locate the overload.
  2. Replace the HTR-A/C fuse 12.

Is the repair complete?

--

Go to HVAC Blower Controls System Check

--

4
  1. Place the ignition switch in the RUN position.
  2. Turn the HVAC control mode switch out of the OFF position.

Does the blower motor operate?

 

Go to HVAC Blower Controls System Check

Go to Step 5

5
  1. Disconnect the front blower motor connector.
  2. Connect a test lamp J 35616-200 from CKT 65 (PPL) cavity A and CKT 350 (BLK) cavity B.

Did the test lamp light?

--

Go to Step 6

Go to Step 7

6

Replace the front blower motor.

Refer to Blower Motor and Fan Replacement .

Is the repair complete?

--

Go to HVAC Blower Controls System Check

--

7

Connect a test lamp J 35616-200 from the front blower motor connector CKT 65 (PPL) cavity A to ground.

Did the test lamp light?

--

Go to Step 8

Go to Step 9

8
  1. Disconnect the blower motor resistor and relay pack.
  2. Connect a DMM J 39200 between CKT 350 (BLK) cavity C and ground.

Is there continuity?

--

Go to Step 10

Go to Step 11

9
  1. Reconnect the front blower motor connector.
  2. Use a test lamp J 35616-200 in order to backprobe from the HVAC control module connector C2 CKT 141 (ORN) cavity E to ground.

Did the test lamp light?

--

Go to Step 13

Go to Step 12

10

Inspect CKT 350 (BLK) for an open between the front blower motor and the blower motor resistor and relay pack.

Does an open exist?

--

Go to Step 14

Go to Step 15

11

Repair the open in CKT 350 (BLK) between ground G100 and the blower motor resistor and relay pack.

Is the repair complete?

--

Go to HVAC Blower Controls System Check

--

12

Repair the open in CKT 141 (ORN) between the HVAC control module and the instrument fuse block.

Is the repair complete?

--

Go to HVAC Blower Controls System Check

--

13
  1. Turn the mode switch out of the OFF position.
  2. Use a test lamp J 35616-200 in order to backprobe from the HVAC control module connector C2 CKT 119 (WHT) cavity G to ground.

Did the test lamp light?

--

Go to Step 17

Go to Step 16

14

Repair the open in CKT 350 (BLK) between the front blower motor and the blower motor resistor and relay pack.

Is the repair complete?

--

Go to HVAC Blower Controls System Check

--

15

Replace the blower motor resistor and relay pack.

Refer to Blower Motor Resistor Replacement .

Is the repair complete?

--

Go to HVAC Blower Controls System Check

--

16

Replace the HVAC control module.

Refer to Control Assembly Replacement .

Is the repair complete?

--

Go to HVAC Blower Controls System Check

--

17

Use a test lamp J 35616-200 in order to backprobe from the HVAC control module connector C3 CKT 119 (WHT) cavity A to ground.

Did the test lamp light?

--

Go to Step 19

Go to Step 18

18

Repair the open in CKT 119 (WHT) between the connector C2 cavity G and the connector C3 cavity A of the HVAC control module.

Is the repair complete?

--

Go to HVAC Blower Controls System Check

--

19
  1. Disconnect the blower motor resistor and relay pack.
  2. Place the fan switch in the HIGH position.
  3. Connect a test lamp J 35616-200 from CKT 52 (ORN) cavity B at the blower motor resistor and relay pack connector to ground.

Did the test lamp light?

--

Go to Step 15

Go to Step 16