Cooling Fan Malfunctions - Troubleshooting

The illustrations show the run-on thermo switch of the cooling fan: on the left for the 4-cylinder engine, on the right for the 5-cylinder engine.

PROCEDURE

First check the corresponding fuse in the auxiliary relay box on the left under the instrument panel (see Body Electrical System chapter).

If it is good, disconnect the thermo switch connector.

Connect both terminals in the wire connector with a piece of wire.

On a two-stage thermo switch, connect all three connector blades.

If the fan starts running with the ignition switched on, the thermo switch is faulty and is removed from the circuit (test jumper).

To continue driving, secure the wire firmly in the connectors and insulate it with adhesive tape or plaster to prevent a short circuit.

If disconnecting the thermo switch does not solve the problem, check the fan relay in the central junction box (see Body Electrical System chapter): if both thermo switch jumpers are bypassed, the relay contacts should audibly close with the ignition switched on.

If nothing is heard, bypass the relay using auxiliary means. To do this, connect the blades of the relay connector at terminals 30 and 87 with a piece of wire (paper clip) and insert the relay.

The cooling fan should now run even with the ignition switched off. If this happens, the relay is faulty.

In an emergency, the jumper wire may remain installed while driving. After completing the trip, it must be removed.

If there is still no reaction, check the fan motor:
Disconnect the wire terminal at the fan motor and instead run an auxiliary wire from the red-black wire contact to the positive battery terminal. Connect the brown wire connector directly to the negative battery terminal.

If the impeller still does not rotate, the fan motor is faulty and must be replaced.

If the fan starts running, check the relay (see Body Electrical System chapter), the wire terminals, and all cable connections from the thermo switch and fan.

You can safely continue driving even with the fan powered directly from the battery. Route the auxiliary wiring so that a short circuit cannot occur.

On appropriately equipped models, the second fan speed or the run-on fan control receives power through the red-blue wire. To check this fan speed, connect the "+" wire to the red-blue wire of the motor connector.