What is the reason for BMW fan output stage detecting an open load circuit?
1 Answers
BMW fan output stage detects an open load circuit due to reasons such as coil overheating damage or absence of 220V AC input, as detailed below: Coil overheating damage: Prolonged use of the fan causes excessive dust accumulation, increasing the friction coefficient between the rotor and bearings, leading to rotor obstruction or even seizing, resulting in coil overheating damage. Solution: After powering off, open the rear cover of the fan, add a few drops of lubricating oil to the bearing sleeves at both ends of the rotor, and rotate the blades while adding oil until they move freely, thereby eliminating the blower fault. No 220V AC input: This may be due to the absence of 220V AC input or coil damage. Solution: Disconnect the power, separate the two lead wires of the fan from the power supply connection points, leaving them suspended. Turn on the power and carefully measure both ends of the power line with a test pen. If one end lights up and the other does not, it indicates the power input is normal, and the issue might be with the fan coil. If both ends do not light up, it suggests a problem with the power input line.