How Do You Test Your Volvo XC90 Cooling Fan Relay? Most modern cars employ liquid-based cooling systems to keep their engine temperature stable. This system works by perpetually circulating coolant between the engine and radiator. The coolant- which is a mixture of ethylene or propylene glycol and water flows through passages in the engine block and head to absorb the heat generated by the engine and then moves to the radiator to disperse that heat to the outside air. The cooling fan, located at the anterior end of the radiator employed to push or pull cool air through the radiator core to facilitate heat exchange between the hot coolant inside and the cool air outside. The operation of the radiator fan is regulated by a relay which in turn is controlled by the engine management computer or ECU.
What’s a cooling fan relay and how does it work? As the name suggests, it is a kind of electromagnetic switch that can turn on or off the electric power supply to the cooling fan. It is of the following types; Open relay- employs an open armature Closed relay- here armature is closed Dual relay- has both open and closed armatures When the engine management computer finds out that your vehicle's engine is running hot, it would send a low voltage signal to the relay in an attempt to energize the cooling fan and facilitate the heat exchange between the radiator and outside air. The use of this type of relay system to regulate different types of computercontrolled devices minimizes stress on your vehicle's electric system. A rise in the engine temperature due to a malfunctioning cooling fan relay can give rise to all sorts of drivability issues in your Volvo XC90. So, learn to recognize the signs of a bad cooling fan relay in your car so that you can replace it on time.
Symptoms of a bad cooling fan relay in Volvo XC90 Engine is running hot This is by far the clearest indicator of a bad cooling fan relay in your car. The engine temperature should stay within 195 to 220 degrees F. The cooling system, combined with the ECU makes sure that the engine temperature stays within that range. However, having a bad cooling fan relay can make your Volvo XC90’s cooling system inefficient, resulting in a significant rise in the engine temperature. Therefore, if you’re noticing that your car engine is running at an elevated temperature than usual, you should immediately check if its cooling fan relay is working fine or not. If it has some issues, consider installing new ones.
Cooling fan is not working As explained earlier, the cooling fan relay essentially allows the battery voltage to be provided to the radiator fan. When energized, the radiator fan pulls air from the outside to cool off the coolant that circulates within the radiator. Once the engine temperature reaches optimal range, the relay turns off the cooling fan. However, a faulty relay mightn't be able to keep up with the electric energy demand of your vehicle's cooling fan, as a result of which it might cease operation.
Cooling fan keeps running When there’s a problem with the cooling fan relay, your Volvo XC90’s radiator fan may stay on all the time. Technical flaws in the system may cause the relay to stay on even when your car’s engine is off. It would ultimately drain the battery power and give rise to a whole new set of problems. Therefore, it’s in your best interest to figure out the reason why your car cooling fan keeps running and fix it.
Blinking warning lights A faulty cooling fan relay can make your car engine run hot and perform poorly. When the engine management computer finds out about this problem, it would turn on different types of warning lights like check engine and temperature warning light in an attempt to warn the driver about the problem.
What causes the cooling fan relay to go bad? Explained below are a few plausible reasons why your Volvo XC90's cooling fan relay can fail prematurely;
ECU problem Malfunctioning sensors Faulty relay controller Electrical short Bad wiring
How to test the cooling fan relay in your car? To test the cooling fan relay in your Volvo XC90, you have to locate it. You can find it in the engine compartment or attached to the fan assembly. After you locate it, you can evaluate its condition by measuring its resistance. If the reading is between 40 to 80 ohms, then it’s fine. If not, consider replacing it right away.
In conclusion The cooling fan relay is a kind of electromagnetic switch that controls the electric power supply to the radiator fan. Disruption in the electric power supply to the radiator fan due to a faulty relay can make your car engine run hot and perform poorly. So, you have to diagnose and fix it without delay.