GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Oldsmobile 🢒 1999 🢒 Cutlass 🢒 Engine 🢒 Engine Cooling 🢒 Cooling Fan Circuit Diagnosis

Step

Action

Value(s)

Yes

No

1
  1. Disconnect the auxiliary cooling fan relay.
  2. Connect a test lamp between the auxiliary cooling fan relay connector cavity 30 and ground.

Does the test lamp light?

--

Go to Step 2

Go to Step 8

2
  1. Move the ignition switch to the Run position.
  2. Connect a test lamp between the auxiliary fan relay connector cavity 85 and ground.

Does the test lamp light?

--

Go to Step 3

Go to Step 9

3

Connect a fused jumper between the Auxiliary Cooling Fan Relay connector cavity 30 and cavity 87.

Does the Auxiliary Cooling Fan Motor run?

--

Go to Step 5

Go to Step 4

4

Connect a self-powered test lamp between the auxiliary cooling fan motor connector cavity A and ground.

Does the test lamp light?

--

Go to Step 10

Go to Step 11

5
  1. Move the ignition switch to the Off position.
  2. Disconnect all Vehicle Control Module (VCM) connectors.
  3. Connect a self-powered test lamp between VCM connector C4 terminal 6 and the auxiliary cooling fan relay connector cavity 86.

Does the test lamp light?

--

Go to Step 6

Go to Step 12

6
  1. Re-connect the auxiliary cooling fan relay.
  2. Move the ignition switch to the Run position.
  3. Connect a fused jumper between VCM connector C4 terminal 6 and ground.

Does the auxiliary cooling fan motor run?

--

Go to Step 7

Go to Step 13

7
  1. Leave the ignition switch in the Run position.
  2. Push the Recirculation button on the Heater and A/C Control Panel in to the ON position.
  3. Connect a test lamp between VCM connector C4 terminal 7 and B+.

Does the test lamp light?

--

Go to

Powertrain On Board Diagnostic (OBD) System Check

Go to Step 14

8

Repair an open in the ORN (1540) wire between the underhood fuse relay center and the auxiliary cooling fan relay.

Is the repair complete?

--

System OK

--

9

Repair an open in the ORN (1250) wire between the underhood fuse relay center and the auxiliary fuse relay center.

Is the repair complete?

--

System OK

--

10

Check for an open in the RED (702) wire between the auxiliary cooling fan relay and the auxiliary cooling fan motor. If OK, replace the auxiliary cooling fan motor.

Is the repair complete?

--

System OK

--

11

Repair an open in the BLK (250) wire between the auxiliary cooling fan motor and G112.

Is the repair complete?

--

System OK

--

12

Repair an open in the DK BLU (473) wire between the VCM and the auxiliary cooling fan relay.

Is the repair complete?

--

System OK

--

13

Replace the auxiliary cooling fan relay.

Is the repair complete?

--

System OK

--

14
  1. Inspect for an open in the DK GRN (1614) wire between the VCM and the Heater and A/C Control Module.
  2. Replace the Heater and A/C Control Module if there is no open in the DK GRN (1614) wire between the VCM and the Heater and A/C Control Module. Refer to HVAC Module Assembly Replacement .

Is the repair complete?

--

System OK

--