What causes the turn signal to intermittently fail and then work normally?
2 Answers
Possible causes include loose wiring or a faulty flasher relay. Here are the relevant details: 1. Turn Signal: The turn signal is an important indicator light that activates when a motor vehicle is turning to alert surrounding vehicles and pedestrians. The turn signal bulb uses a xenon tube, controlled by a microcontroller circuit, with alternating left-right flashing operation. The turn signal employs a flasher to achieve the blinking effect, which can be mainly categorized into three types: thermal (bimetallic strip), capacitor, and electronic. 2. Flasher Relay: Also known as a flasher, its function is to generate intermittent current to supply the turn signal lights, making them flash on and off to indicate the vehicle's direction. The flasher features a new circuit design consisting of a low-voltage switch circuit, high-voltage switch circuit, pulse generation circuit, two-stage amplifier with dual-transistor output circuit, and two sets of light indicator circuits.
I've seen quite a few cases where turn signals work intermittently, usually caused by poor contact. After prolonged use, the internal contacts in the turn signal switch may rust or wear out, resulting in intermittent signals when turning. The flasher relay is another common failure point - burnt contacts or coil issues inside can cause unstable light flashing. Additionally, aging wiring is a concern, such as loose plugs or corroded wires which are more prone to problems in humid environments. Simple checks first: move the turn signal stalk to check for stiffness; open the fuse box to inspect if the relay is overheating or making unusual sounds. With tools, you can test circuit continuity to locate breaks. Not fixing this poses significant risks: non-functioning signals during turns may confuse following drivers and increase accident rates. Regular cleaning of contact points can prevent such issues.
