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 right cooling fan turn OFF?

Go to Step 6

Go to Step 7

5

Repair the short in the cooling fan motor supply voltage circuit of the left cooling fan. 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 cooling fan low reference circuit of the left cooling fan. 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 cooling fan motor supply voltage circuit of the right cooling fan. 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