Why does the car turn signal intermittently fail?
4 Answers
Intermittent failure of the car turn signal is usually caused by a faulty flasher relay or turn signal switch. Below are the specific causes and solutions: Flasher relay failure: If the flasher fails, it will cause both the left and right turn signals of the vehicle to not work. Solution: In this case, the general solution is to replace the flasher. Turn signal switch failure: If the turn signal switch of the vehicle fails, it will cause either the left or right turn signal to not work. Solution: For this situation, it is generally recommended to go to a repair shop for maintenance and replace the faulty turn signal switch.
Intermittent failure of car turn signals is quite common, and I often repair this type of issue. The most frequent causes are loose or oxidized bulb sockets, which result in intermittent current flow, and the problem worsens with vibration. Next, check the turn signal switch—worn or dirty contacts inside the switch can cause poor connectivity. Then inspect for aging or damaged wiring, especially in areas where the steering wheel rotates, as wires there are prone to breaking or short-circuiting. Relay failure is also a concern; a burnt-out flasher relay can cause erratic blinking. Start with simple checks: wiggle the bulb socket by hand to see if the light turns on, and try replacing the fuse. If that doesn’t work, take it to a professional shop to test the relay and wiring immediately—don’t delay. Ignoring this issue increases risks when changing lanes or turning while driving. Safety first—never take such problems lightly.
My car had the same issue last month, the lights would flicker a few times and then go out. At first, I thought it was a burnt-out bulb. After taking it apart, I found the socket was rusty. Cleaning it helped a bit but didn't solve the problem completely. Then I noticed the turn signal switch was sticking, causing the contacts to intermittently connect and disconnect when turning the handle. There was also some wiring damage under the hood causing a minor short circuit. Another time, it was a burnt-out relay, which stabilized after replacement. When doing your own inspections, pay extra attention to loose circuit connections. Address these issues promptly to avoid nighttime driving accidents. Replacing parts isn't expensive, usually just a few dozen bucks. Even beginners can do simple troubleshooting—don't let small problems escalate. Remember to clean related components during maintenance.
Turn signal flashing issues may stem from control module or sensor problems. Modern vehicles have electronic control units for management; moisture exposure or software glitches in the module can cause intermittent failures. Loose wiring connections are also common, especially in high-vibration areas like near the wheels. A blown fuse can lead to momentary interruptions. Simple inspection methods: use a multimeter to test circuit continuity, or observe light fluctuations after startup. Safety tip: When malfunctioning, using hand signals to indicate turns is more reliable before seeking repairs. Never ignore this issue to prevent rear-end collisions.
