A cooling fan relay is important in keeping the engine cool. It functions to covert low voltage signal coming from either a thermostatically controlled sensor or that of the electronic control module. It switches the relay on so that the battery voltage can be supplied to the radiator. Having problems with your Volvo's cooling fan relay? Here is how you can replace one.
Removing the Cooling Fan Relay in the Relay Box
Simply locate the relay box. This is typically found on either on the passenger or driver side of the engine compartment found near the fender. Remove the cover found on top of the relay box, by releasing the fasteners or retaining clips found on it. From here, you can locate the cooling fan relay. Some manufacturers print a diagram that maps the relays and fuses found inside the relay box. In case you do not have one, you can always refer to the owner's manual.
Replace the Cooling Fan Relay
The ignition key must be in the off position, Make sure that the power is off as well. It is best to take the key out of the ignition. This will ensure that no voltage spikes will cause damage to the ECM while you are placing the cooling fan relay. When you are ready to replace the relay, just simply pinch the assembly with your fingers, wiggling it back and forth, while also pulling the relay up gently. This process can be more difficult if debris and dirt have already built up on the relay. When this is the case, you will need to use a pair of pliers or a small screwdriver to help you out.
Once the old relay has been removed, check that the replacement relay you have matches it. Check that the basic dimensions are the same. Compare terminal numbers as well as the relay orientation by flipping it over.
Install the New Cooling Fan Relay
Position the new relay such that it is found above the recess where the previous relay has been removed. Gently press the new part into place. Make sure that it has been seated properly on the spot. The base of the cooling fan relay must be completely seated into the socket. Check that the replacement works. Warm up the engine then turn the air conditioning system.
Cooling fan relay replacement can vary depending on where the relay has been mounted. If it is mounted directly to the cooling fan assembly, you will need to follow another procedure. In this regard you also need to disconnect electrical connectors before replacing the old relay. Install the new one following the procedures above, paying particular attention to how the original assembly was placed.
You can use some help by sending your car to an auto mechanic. Make sure you get genuine Volvo parts to ensure that your new relay will work as expected. It will be a good idea to check on the vehicle's manual so that you can easily find out the part that you are looking for.