What is the fault when the car air conditioner has no power?

[McCharles]

Faults that cause the car air conditioner to have no power are as follows: 1. Compressor wear: Severe internal wear of the compressor leads to its inability to function properly. The compressor plays a crucial role in the air conditioning system, primarily compressing and delivering refrigerant, which causes it to operate at high speeds for extended periods, resulting in malfunction. 2. Lack of refrigerant in the car air conditioner: The compressor is used to compress and deliver refrigerant. If the refrigerant leaks, there is no refrigerant to compress or deliver, causing the compressor to fail. 3. Electrical system failure: Electrical system failures are a very common reason for the car air conditioner compressor not working properly. You can check if the circuit is unobstructed and inspect the temperature sensor and solenoid valve.

[DiZachary]

Last time the AC panel went black, I directly opened the glove compartment to check the fuse box, and sure enough, the 15A mini fuse was burnt black. I casually replaced it with a spare fuse and fixed the issue. Later, I found out it was caused by a chain reaction from a short circuit in the car charger. Malfunctioning AC buttons might also be due to desoldered control panel circuits—my old car had a loose panel connector, and surprisingly, tightening it with a toothpick did the trick. However, if the blower runs but no air comes out, it's most likely a burnt resistor module, which requires dismantling the center console to repair. The most troublesome issue is when the BCM control module fails, causing the entire AC system to collapse, leaving no choice but to visit the dealership for computer diagnostics to read the fault codes.

[JustinFitz]

From my experience, air conditioning power failure can be categorized into three levels: Primary level - check the fuse, look for the F-marked box under the steering wheel; Intermediate level - listen for relay clicking sounds, locate the AC relay in the engine compartment fuse box; Advanced issues - inspect control circuits. Last week encountered a case where aftermarket dashcam installation caused a short circuit - removing it restored functionality. For older vehicles, beware of rodent-chewed wiring harnesses (rubber smell gives it away). For audio-modified cars, pay special attention to amplifier wiring interfering with AC module - dashboard code 01287 indicates this scenario. Proper AC repair requires diagnostic tool data stream analysis - voltage measurement alone is useless.

[VictoriaAnn]

When the AC fails, do three things first: With power on, press your ear against the center console to listen for the blower's hum; check near the throttle pedal to see if the temperature control motor is stuck; open the hood to check if the compressor clutch engages. 80% of faults lie in the blower resistor, located above the passenger footwell—replace it by removing three screws in ten minutes. A burnt smell indicates relay contact issues requiring immediate attention. For modified one-button start systems, aftermarket devices may cause abnormal AC module sleep mode.

[AnnaLee]

The air conditioning circuit is like capillaries: the thin wires branching from the cigarette lighter fuse are most prone to melting; dislodged control panel wiring can cause button malfunctions; a short circuit in the sunlight sensor can directly lock the system. I've disassembled three fan blades inside the blower—iron powder from worn carbon brushes can clog the motor. A key diagnostic trick is to measure the panel backlight voltage with a multimeter—no current means a main circuit break. Pay special attention to clogged evaporator drain pipes causing water to seep into the circuit board—repairing this can cost over two thousand.

[TaylorLee]

Different issues for new and old cars: For cars under five years old, it's mostly automatic AC sensor failure, shown by the screen lighting up but no cold air blowing; older cars often have blower bearing seizure causing resistor burnout, accompanied by a burnt smell. Owners who modified headlights, beware that inferior ballasts can cause current backflow and burn out the AC fuse. Special cases include the AC module being locked by the anti-theft system, requiring an ECU reset by disconnecting the power. During the rainy season, first check if the engine compartment fuse box is flooded, as aging rubber seals are the main culprit.