Will the hazard lights break after flashing for 12 hours?

[MacRylee]

No, the hazard lights can flash for a whole day and night when the car is turned off, as the car battery is large and the hazard lights consume little power. Relevant explanations are as follows: 1. Check the control box: If the hazard lights suddenly start flashing automatically, it is likely due to a problem with the control box. You need to check whether the hazard light relay is functioning properly. Use a multimeter to measure the output line of the hazard light relay to see if there is a 12v output. 2. Replace with a new one: If there is intermittent output variation, it means the relay is normal. If there is no output or a constant 12v output, it indicates that the hazard light relay is damaged and needs to be replaced with a new one.

[MacHazel]

The day before yesterday, I accidentally turned on the hazard lights with my car key, and after they were on for a full day, I found that two bulbs had indeed burned out. Actually, the hazard light system has a dedicated 15A fuse for protection, but for halogen bulbs working continuously at high temperatures for 12 hours, filament evaporation accelerates aging, especially in older cars that are five or six years old. There's no need to worry too much about the wiring—modern car wires can generally withstand temperatures starting at 120 degrees. The biggest concern is the battery draining—I’ve tested it, and hazard lights consume about 0.3 kWh per hour. An old battery might not last 12 hours and could just die. If the car starts normally after using the hazard lights, it’s likely just the bulbs that have taken a hit. Next time, remember to check the turn signal frequency—if it speeds up or slows down, it’s a sign that the relay is about to fail.

[AdrianAnn]

The neighbor's kid kept pressing the hazard light switch randomly, leaving them on all night, which later caused the bulb contacts to burn black. Normally, automotive-grade relays are designed for 30,000 switching cycles. Continuous flashing for 12 hours is equivalent to 4,000 high-intensity operations, making the contacts prone to melting and sticking. The most extreme case I've seen was a fuse box plastic part deformed by heat, but that was on a car with cheap aftermarket LED lights. Although factory halogen bulbs generate more heat, models with well-designed heat dissipation vents rarely have issues. Key things to check: any burnt smell after power-on, and whether the lamp housing is too hot to touch—anything above 80°C is a red flag. It's advisable to keep two H21W spare bulbs on hand, as prolonged usage like this often requires replacement.

[VonMaci]

Last winter, my car was buried in snow, and the hazard lights automatically stayed on all night. This situation is the ultimate test for wiring: the factory wiring harness wrapped in heat-resistant materials can handle it, but modified wiring tends to have melted insulation. Check three critical points: flasher temperature, fuse box humidity, and battery voltage. Experience shows that if the hazard lights operate continuously for 12 hours with a cold engine, and the battery voltage drops below 10V, it's dangerous and could damage the ECU. Fortunately, modern cars have low-voltage protection. If you notice the hazard lights flickering irregularly, it's usually a sign the relay is failing—just replace it with a fifty-dollar part. If you're really worried, scan for trouble codes; OBD can always detect electrical issues.