Cooling Fan Inoperative Main
| Table 1: | Reference Table |
Problem | Causes | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Both fans inoperative |
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Main fan inoperative |
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Auxiliary fan inoperative |
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Both fans inoperative in low speed |
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Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Engine Cooling Schematics . | |||
The main fan motor is mounted on the left side of the radiator/condenser assembly. The fans run at low speed in 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 in parallel configuration when the ECT is above 93°C (199°F). A short to ground in the coil ground circuit of the fan 1 and 2 relays will cause both fans to be inoperative once the ECT reaches 93°C (199°F). This table assumes that the auxiliary fan motor is functioning normally. | |||
1 | Did you review the Cooling System Description and Operation and perform the necessary inspections? | Go to Step 2 | |
2 | Run the engine until operating temperature is reached and the thermostat opens. Do the cooling fans operate? | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 3 |
3 | Exchange the fan 1 relay with a known good relay (the fan 3 relay, the A/C MG relay, or the horn relay). Refer to Cooling Fan Relay Replacement . Did you find and correct the condition? | Go to Step 14 | Go to Step 4 |
4 |
Does the test lamp illuminate? | Go to Step 12 | Go to Step 5 |
5 | Test the main fan motor ground circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 14 | Go to Step 6 |
6 | Test the main fan motor supply voltage circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 14 | Go to Step 7 |
7 | Test the supply voltage circuit to fuse and relay block 1 for an open. This circuit supplies voltage to the coils of the fan 1 relay and the engine main relay. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 14 | Go to Step 8 |
8 | Test the fan 1 relay switch supply voltage circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 14 | Go to Step 9 |
9 | Test the engine main relay switch supply voltage circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 14 | Go to Step 10 |
10 | Test the engine main relay control circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 14 | Go to Step 11 |
11 |
Did you find and correct the condition? | Go to Step 14 | -- |
12 | Inspect for a poor connection at the harness connector of the main fan motor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 14 | Go to Step 13 |
13 | Replace the main fan motor. Refer to Engine Cooling Fan Replacement . Did you complete the replacement? | Go to Step 14 | -- |
14 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 3 |
Cooling Fan Inoperative Auxiliary
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Engine Cooling Schematics | |||
The auxiliary fan motor is mounted on the right side of the radiator/condenser assembly. The fans run at low speed in 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 in parallel configuration when the ECT is above 93°C (199°F). A short to ground in the ground circuit of the fan 1 and 2 relays will cause both fans to be inoperative once the ECT reaches 93°C (199°F). This table assumes that the main fan motor is functioning normally. | |||
1 | Did you review the Cooling System Description and Operation and perform the necessary inspections? | Go to Step 2 | |
2 | Run the engine until operating temperature is reached and the thermostat opens. Do the cooling fans operate? | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 3 |
3 |
Does the test lamp illuminate? | Go to Step 7 | Go to Step 4 |
4 | Test auxiliary fan motor supply voltage circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 9 | Go to Step 5 |
5 |
Did you find and correct the condition? | Go to Step 9 | Go to Step 6 |
6 | Replace the fan 2 relay. Refer to Cooling Fan Relay Replacement . Did you complete the replacement? | Go to Step 9 | -- |
7 | Inspect for a poor connection at the harness connector of the auxiliary fan motor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 9 | Go to Step 8 |
8 | Replace the auxiliary fan motor. Refer to Engine Cooling Fan Replacement . Did you complete the replacement? | Go to Step 9 | -- |
9 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 3 |
Cooling Fan Inoperative Inop in Low Speed
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Engine Cooling Schematics | |||
The main fan motor is mounted on the left side of the radiator/condenser assembly. The auxiliary fan motor is mounted on the right side of the radiator/condenser assembly. The fans run at low speed in 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 in parallel configuration when the ECT is above 93°C (199°F). A short to ground in the ground circuit of the fan 1 and 2 relays will cause both fans to be inoperative once the ECT reaches 93°C (199°F). This table assumes that the parallel portion of the circuit and the A/C system are functioning normally. Therefore, the malfunction is in the series portion of the circuit. | |||
1 | Did you review the Cooling System Description and Operation and perform the necessary inspections? | Go to Step 2 | |
2 |
Do the cooling fans operate at low speed? | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 3 |
3 | Exchange the fan 3 relay with a known good relay (the fan 1 relay, the A/C MG relay or the horn relay). Do the cooling fans operate at low speed? | Go to Step 8 | Go to Step 4 |
4 | Test the fan 3 relay coil supply voltage circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 9 | Go to Step 5 |
5 | Test the fan 3 relay coil ground circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 9 | Go to Step 6 |
6 | Test the circuit between the fan 3 relay and the fan 2 relay for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 9 | Go to Step 7 |
7 | Test the fan 3 relay switch supply voltage circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 9 | -- |
8 | Replace the fan 3 relay. Refer to Cooling Fan Relay Replacement . Did you complete the replacement? | Go to Step 9 | -- |
9 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 3 |
