Cooling Fan Relay Replacement - Auxiliary Motorhome

The auxiliary cooling fan provides additional cooling under the following conditions:

The auxiliary cooling fan circuit consists of the following components:

When the coolant sensor reaches a predetermined temperature, the sensor closes the circuit to the relay coil. The relay coil energizes the relay, which passes 12 volts to the auxiliary fan. The system also operates on refrigerant system pressure. When the coolant temperature decreases below the sensor set-point, the circuit to the relay opens. This causes the 12 volt power to the auxiliary fan to stop.

In order to replace the auxiliary cooling fan, refer to Condenser Replacement in HVAC.

Removal Procedure

Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.

1. Disconnect the negative battery cable.
2. Disconnect the wiring harness connector.
3. Disconnect the fan relay from the brake pedal bracket.

1. Connect the relay to the brake pedal bracket.
2. Connect the wiring harness connector.
3. Connect the negative battery cable.

Removal Procedure

1. Drain the coolant from the system.

Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.

2. Disconnect the negative battery cable.
3. Disconnect the wiring harness connector.
4. Remove the coolant temperature sensor.

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

1. Install the coolant temperature sensor.

Tighten
Tighten the coolant temperature sensor to 23 N·m (17 lb ft).

2. Connect the wiring harness connector.
3. Connect the negative battery cable.
4. Fill the system with the recommended coolant.