REMOVAL & INSTALLATION
The radiator cooling fans are electrically operated and mount directly to the radiator.
- Note the radio security code and disconnect the negative battery cable.
- Detach the electrical connectors and wiring guide brackets for the cooling fans
- If additional work space is needed, drain about 3 quarts of coolant from the radiator into a sealable container by loosening the radiator drain plug, then disconnect and plug the upper radiator hose.
On V6 Odyssey models:
- Remove the positive battery cable and remove the battery.
- Disconnect the wire harness guides from the battery tray.
- Remove the ground strap and the relay box bracket from the battery tray.
- Remove the battery tray mounting bolts and remove the battery tray.
- Remove the wire harness holders from the upper radiator support, and disconnect the electrical connectors for the Air Conditioning compressor clutch.
- Remove the fan shroud mounting bolts.
- On CRV and 4-cylinder Odyssey models, carefully remove the cooling fan assembly from the vehicle.
- On V6 Odyssey models, carefully remove the cooling fans from the battery side of the vehicle.
- The installation is in the reverse order of removal except for the following steps.
- Top off and bleed the cooling system as necessary.
- When connecting the battery cables, connect the positive battery cable first, then the negative cable.
- Enter the radio security code.
- Start the engine and check for coolant leaks and normal operation of the cooling fans.
The electric cooling fans are electrically operated and controlled by two basic electrical circuits. One of the electrical circuits has a temperature sensor which triggers a relay to power the fans. The cooling fan will begin to operate once the coolant temperature reaches the designated temperature of the temperature sensor, which completes the circuit for the fan relay causing the fan to operate.
Possible failures in this circuit include the following:
Possible cooling system problems that could affect the cooling fan operation include:
The second electrical circuit that controls the cooling fans is the air conditioner circuit. When the air conditioning is used, the cooling fans automatically operate, regardless of the engine coolant temperature.
This can be a handy tidbit of information to know should the temperature sensor fail. If the air conditioner is turned on, the cooling fans should function if the A/C system is in proper working order.
Possible failures in this circuit include a faulty A/C switch as well as those items from the previous list.
Electric cooling fan circuit failures can be one of several types:
The danger of a cooling fan that fails to operate is an overheated engine. A cooling fan that runs all the time only when the ignition is ON never allows the engine to fully warm up, and driveability and fuel economy may suffer. A cooling fan that runs all the time even when the ignition is switched off, never allows the engine to fully warm up, the driveability and fuel economy may suffer, and the battery will eventually discharge.
To test the cooling fans, proceed as follows:
- Detach the electrical connector for the cooling fan. Consult the wiring schematics in Chassis Electrical for the exact wire color for each fan. The black wire is ground and the colored, striped wire is positive.
- Carefully connect a 30 amp fused jumper wire between the fan positive wire and the battery positive terminal.
- Connect a jumper wire between the fan ground terminal and a known good chassis ground and the fan should operate. If the fan fails to operate, check the test circuit with a known good 12 Volt test light to make sure the jumper leads are functioning properly. If the circuit tests OK and the fan fails to function when connected to the jumper circuit, replace the fan. If the jumper circuit fuse blows, check for a shorted fan wire and test again. If the jumper circuit continues to blow the fuse the fan motor is internally shorted and must be replaced.