What is the reason for the electric fan not working when the air conditioner is turned on in an old Polo?
4 Answers
There are several reasons why the fan does not rotate when the air conditioner is turned on in an old Polo, including poor motor lubrication, reduced starting capacitor capacity, and prolonged motor usage. Below are the detailed explanations: 1. Poor motor lubrication: The fan does not rotate because the motor lacks sufficient lubrication, preventing it from driving the fan blades after installation. 2. Reduced starting capacitor capacity: The capacitor capacity decreases, leading to a reduction in the motor's starting torque, making it unable to drive the load. 3. Prolonged motor usage: After prolonged use of the fan, the motor wears out. When the motor's shaft sleeve wears, it is prone to burning out. Extended use of the motor also increases its internal resistance, reducing its load-bearing capacity and preventing it from driving the fan blades.
As a seasoned auto mechanic with years of experience, I often encounter cases where the electric fan fails to work when the AC is turned on in older Polo models. There are several common causes for this issue. First, the fan fuse may be blown—it can be found in the engine compartment's fuse box, and this is the easiest to check. Second, relay failures, such as aging AC relays or fan relays, are common in older cars where worn components can disrupt electrical flow. Third, a faulty coolant temperature sensor may misread the temperature and prevent the fan from spinning, affecting the cooling of the AC condenser. Additionally, the electric fan motor itself might be stuck or burned out, and corroded or loose wiring connectors are also frequent issues in older Polos. If you face this problem, avoid long-distance driving—pull over and inspect basic components first to prevent engine overheating and AC system damage. I recommend visiting a professional repair shop for a thorough check-up early on to prevent minor issues from escalating.
As an automotive tech enthusiast, I've found that when retrofitting old Polos, AC fan failures are often caused by electrical system issues. For instance, control unit malfunctions, ECU signal errors, or sensor failures can prevent the fan from activating. Wiring shorts or open circuits shouldn't be overlooked either - older vehicle wiring harnesses are prone to aging and current leakage. Additionally, relay contact erosion or voltage instability could be culprits, all of which can be easily tested with a multimeter. My recommendation is to start troubleshooting from the fuse box by replacing fuses; if that doesn't work, check the fan's resistance values. Worth noting: the electric fan is a core AC component - its failure causes rapid condenser temperature spikes, compromising cooling efficiency and potentially engine longevity. While DIYers can handle some diagnostic steps, I'd advise consulting professionals promptly to eliminate safety hazards.
As a long-time owner of an old Polo, I've found that when the AC is on but the electric fan isn't running, it's most likely due to aging components. It could be a blown fuse or a damaged fan motor – these parts tend to fail in older vehicles after prolonged use. Loose wiring or sensor malfunctions can also trigger the protection mechanism. Remember, don't force the AC to work without fixing it first, as this can easily cause the engine to overheat and stall, compromising driving safety. I recommend taking it directly to a 4S shop or professional repair facility for inspection – don't try to save small money at the risk of bigger problems. During regular maintenance, make sure to periodically check the electric fan system – prevention is better than cure.
