For 1990-2009 cars

Step | Action | Yes | No
--- | --- | --- | ---
The fans run at low speed (series configuration) when the A/C is operating and the engine coolant temperature (ECT) is below 83°C (181°F). The fans run at high speed (parallel configuration) when the ECT is above 93°C (199°F). An open in the ground circuit for the fan no. 1 and no. 2 relay coils will cause the fans to run continuously with the ignition switch in the RUN position and the ECT below 93°C (199°F).
The following are symptoms and possible causes.

• | Main fan always ON:

- | Faulty fan no. 1 relay

- | Open in the fan no. 1 relay coil ground circuit

- | Short to voltage in the main fan motor supply voltage circuit

• | Auxiliary fan always ON:

- | Faulty fan no. 2 relay

- | Short to ground in the auxiliary fan motor ground circuit

• | Both fans always ON:

- | Faulty fan no. 3 relay

- | Faulty A/C MG relay

- | Open in the fan no. 2 relay coil ground circuit

- | Short to voltage in the fan no. 3 relay coil supply voltage circuit

- | Engine coolant temperature (ECT) sensor or powertrain control module (PCM) malfunction

1 | Did you perform the HVAC System Check? | Go to Step 2 | Go to the HVAC System Check
2 |

1. Ensure that the ECT is below 93°C (199°F)
2. Depress the A/C switch to the OFF position.
3. Turn the blower switch to the OFF position.
4. Turn the ignition switch to the RUN position.

Is only the main fan motor running continuously?

Go to Step 5

Go to Step 3

3 | Is only the auxiliary fan motor running continuously? | Go to Step 9 | Go to Step 4
4 | Are both fan motors running continuously? | Go to Step 12 | Go to Step 1
5 | Remove the fan no. 1 relay from fuse and relay block 1. Does the main fan motor run? | Go to Step 6 | Go to Step 7
6 | Repair the short to voltage in the BLK/RED wire between the main fan motor terminal 2 and fuse and relay block 1. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | Go to the HVAC System Check | --
7 | Test for an open in the BLU/BLK wire between the fan no. 1 relay in fuse and relay block 1 and the A/C fan no. 2 relay in fuse and relay block 2. Is an open present? | Go to Step 16 | Go to Step 8
8 | Replace the fan no. 1 relay. Refer to Cooling Fan Relay Replacement in Engine Cooling. Is the repair complete? | Go to the HVAC System Check | --
9 | Remove the A/C fan no. 2 relay from fuse and relay block 2. Does the auxiliary fan motor run? | Go to Step 10 | Go to Step 11
10 | Repair the short to ground in the WHT wire between the auxiliary fan motor terminal 1 and fuse and relay block 2. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | Go to the HVAC System Check | --
11 | Replace the A/C fan no. 2 relay. Refer to Condenser Fan Relay Replacement . Is the repair complete? | Go to the HVAC System Check | --
12 | Remove the A/C fan no. 3 relay from fuse and relay block 2. Do both fan motors run? | Go to Step 13 | Go to Step 18
13 |

1. Test for an open in the BLU/BLK wire between the A/C fan no. 2 relay and the A/C refrigerant pressure switch connector.
2. Test for an open in the LT GRN wire between the A/C refrigerant pressure switch connector and the powertrain control module (PCM).

Is an open present?

Go to Step 16

Go to Step 14

14 | Test for an open in the A/C refrigerant pressure switch. Is an open present? | Go to Step 15 | Go to Step 17
15 | Replace the A/C refrigerant pressure switch, if equipped. Refer to Air Conditioning (A/C) Refrigerant Pressure Sensor Replacement . Is the repair complete? | Go to the HVAC System Check | --
16 | Repair the open/short. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | Go to the HVAC System Check | --
17 | Inspect the ECT sensor for incorrect performance or for an incorrect input to the PCM. Refer to DTC P0116 Engine Coolant Temperature (ECT) Sensor Performance in Engine Controls. If the ECT sensor is operating correctly, replace the PCM. Refer to Powertrain Control Module Replacement in Engine Controls.

Is the repair complete?

Go to the HVAC System Check

--

18 |

1. Test the A/C MG relay for continuity between terminals 3 and 5. Refer to

   #### Fuse and Relay Block 2

   (1) | A/C MG Relay
   (2) | A/C FAN No.3 Relay
   (3) | A/C FAN No.3 Relay
   (4) | Dimmer Relay
   (5) | CDS Fuse 30A
   (6) | HEAD (LH-LWR) Fuse 10A
   (7) | HEAD (RH-LWR) Fuse 10A
   (8) | DRL Fuse 7.5A
   (9) | Fuse and Relay Block 2

   in Wiring Systems.
2. Test the A/C fan no. 3 relay for continuity between terminals 3 and 5. Refer to

   #### Fuse and Relay Block 2

   (1) | A/C MG Relay
   (2) | A/C FAN No.3 Relay
   (3) | A/C FAN No.3 Relay
   (4) | Dimmer Relay
   (5) | CDS Fuse 30A
   (6) | HEAD (LH-LWR) Fuse 10A
   (7) | HEAD (RH-LWR) Fuse 10A
   (8) | DRL Fuse 7.5A
   (9) | Fuse and Relay Block 2

   in Wiring Systems.

Does continuity exist in either relay?

Go to Step 19

Go to Step 20

19 | Replace the faulty relay. Refer to Condenser Fan Relay Replacement . Is the repair complete? | Go to the HVAC System Check | --
20 | Repair the short to voltage in the BLK/WHT wire between the A/C fan no. 3 relay terminal 1 in fuse and relay block 2 and the A/C MG relay terminal 3 in fuse and relay block 2. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | Go to the HVAC System Check | --