GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Engine Cooling Schematics

DEFINITION: One or both engine cooling fan motors run continuously in high or low speed modes.

1

Did you perform the Engine Cooling Diagnostic System Check?

Go to Step 2

Go To Diagnostic System Check - Engine Cooling

2

Turn ON the ignition, with the engine OFF.

Are one or both cooling fans running all the time?

Go to Step 3

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

3

Are both cooling fans running continuously?

Go to Step 5

Go to Step 4

4

Remove the cooling fan S/P relay.

Did the eng cool RH fan turn OFF?

Go to Step 6

Go to Step 7

5

Repair the short in the eng cool LH fan supply voltage circuit. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 8

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6

Repair the short in the eng cool LH fan low circuit. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 8

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7

Repair the short in the eng cool RH fan supply voltage circuit. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 8

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8

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2