What is the reason for the loud noise from the newly replaced controller?
4 Answers
Newly replaced controller makes loud noise due to different connection sequence between the controller and the motor. The following is an introduction about sedan-related content: Introduction: A sedan (saloon-car) refers to a vehicle used to transport people and their personal belongings, with seats arranged between two axles. Including the driver, the maximum number of seats does not exceed nine. Generally, sedans emphasize comfort, focusing on passengers. Moreover, from an economic perspective, they choose engines with moderate horsepower, small displacement, and low fuel consumption. Structure: The body structure of a sedan mainly includes the body shell, doors, windows, front sheet metal parts, interior and exterior decorative parts, body accessories, seats, as well as ventilation, heating, cooling, and air conditioning devices. For trucks and special sedans, it also includes the cargo box and other equipment.
When I first replaced the controller, I also encountered noise issues—it was as loud as a generator. After careful troubleshooting, I realized the installation location matters a lot. Placing it near the engine provides better cooling but increases vibration, which can easily cause resonance and a humming sound. Later, I repositioned it and added damping washers, and it became much quieter. Additionally, unbalanced fan blades in the controller can also cause strange noises, so you might need to disassemble it to check for deformities. Wiring can't be overlooked either—my colleague once had high-frequency squealing from internal components due to unstable current caused by undersized power cables. I recommend using factory-spec wiring and ensuring connectors are fully inserted. Lastly, don’t forget to test load compatibility—if the controller can’t drive the component properly, it may overload and produce abnormal noises.
I've encountered this issue of excessive noise after replacing the controller several times. One critical point often overlooked is improper installation of the cooling system - if not done correctly, the fan will run at full speed continuously. Last time when repairing Old Liu's car, I found the controller's heat sink was blocked by wiring harnesses, trapping hot air and causing the fan to spin wildly. Another common issue is when the controller's base plate isn't tightly attached to the metal body, leading to poor heat dissipation and resulting in high-frequency noise. Additionally, the control program needs proper adaptation - I once encountered a case where flashing the wrong firmware version caused motor drive frequency mismatch and produced a buzzing sound. I recommend checking the controller's shell temperature; if it's too hot to touch, it's likely a heat dissipation problem. If all else fails, consider switching to an industrial-grade controller with triple-proof treatment, which offers better shock resistance.
Controller noise issues boil down to three key points: First is power interference. Once when I replaced an EV controller, the hissing noise was unbearable. Turned out to be loose battery terminals causing voltage fluctuations that made the power transistors whine. Second concerns internal components - newly installed controllers may buzz if power transistors have cold solder joints, or when filter capacitors bulge causing unstable current. Third is mechanical assembly - unsecured case screws can cause resonance. Last time my controller clicked after replacement because the relay wasn't properly fixed to its plastic base. Recommendation: first check power supply stability, then diagnose by sound - high-frequency noise likely indicates capacitor issues while low-frequency vibrations usually mean installation problems.
