It is possible that the wires and connectors are faulty. If you notice that the fan does not work even when the car is overheating, there might be a wiring issue or a bad connection. If this is the case, you must fix them. You should check the wires from the control unit or relay to the radiator fan. Your volvo fan relay is a two stage (speed) relay. It constantly has a 12v feed. As soon the ECU provides low or high speed ground signal to it, it will energize the fan accordingly. Have you started noticing that your air conditioner isn't running quite as cool as it once did? There's a chance that this is related to a defective volvo fan relay. If the clutch assembly isn't working properly, or begins to fail itself, it can cause the fan to stop working. Over time, the clutch assembly will begin to wear and require servicing. Inspecting the clutch assembly for your cooling fan should be a part of routine care for your Volvo. Volvo XC70 Radiator Fan Not Working? RepairPal will help you figure out whether it's your Fan Assembly, Fan Clutch, Coolant Temperature Sensor, or something else. Reasons a Volvo XC90 Radiator Fan Isn't Working. The most common reasons a Volvo XC90 radiator fan isn't working are the fan assembly, the fan clutch, or the coolant temperature sensor. You can test things by grounding, one at a time, the relay pins associated with the yellow and the yellow/white wires that go to the center of the cooling fan relay. One should turn the fan on high speed and the other should turn the fan on low speed. If that works then the fan and the relay are good. M3bm.

volvo cooling fan not working