What Makes the Clicking Sound on a Turn Signal

The clicking sound from a turn signal is produced either by a mechanical relay opening and closing the circuit (common in older vehicles) or by a synthesized chime played through a speaker or instrument cluster (typical in modern cars). Automakers use the sound as intentional feedback so drivers know the indicators are operating; how it’s generated depends on the vehicle’s flasher system and electronics.

How the Sound Is Made

Thermal Flasher Relays (Classic and Older Vehicles)

For decades, turn signals used a thermal “flasher” relay containing a bimetal strip. When you activate the indicator, current flows to the bulbs, heating the strip until it bends and breaks the circuit. As it cools, the circuit closes again. This heating-and-cooling cycle makes the lamps blink—and the relay’s metal contacts produce that familiar tick-tock each time they snap open and shut. Because the timing depends on current draw, a burned-out bulb changes the cadence, often leading to a faster “hyperflash.”

Electronic/Solid-State Systems (Most Modern Vehicles)

Newer cars use solid-state timing controlled by an electronic flasher module or the body control module (BCM). Instead of relying on heat, a microcontroller sets the blink rate and either energizes a small relay that clicks or plays an artificial tick through a piezo buzzer, the instrument cluster, or even the vehicle’s audio speakers. The sound is no longer a byproduct—it’s deliberately generated so drivers still hear it even in quiet cabins.

Where the Sound Comes From in Your Car

Depending on model and year, the audible tick may originate from several locations. Knowing the likely sources can help you identify what you’re hearing and where to look if the sound changes or disappears.

• Under-dash or fuse-box relay: A physical flasher relay that clicks as it opens and closes the circuit.
• Combined hazard/turn flasher unit: A single module handling both functions, often behind the dash.
• Instrument cluster chime: A small speaker or buzzer behind the gauges that plays a synthetic tick.
• Body control module (BCM) or audio system: Some vehicles route the tick through the car’s speakers.
• Steering column switchgear: Light mechanical noises can come from the stalk or canceling cam, but the main tick is usually elsewhere.

Pinpointing the source—by listening near the cluster, under the dash, or around the steering column—can quickly tell you whether your system uses a mechanical relay or a synthesized chime.

Why the Tick Speeds Up or Changes

Changes in the click’s cadence are often diagnostic clues. In systems that monitor load, the blink rate and sound may alter to alert you to faults or unusual conditions.

• Burned-out bulb (common cause): Reduced current leads to hyperflash in thermal or monitored electronic systems.
• LED bulb retrofit without proper resistor or electronic flasher: Low current can trigger rapid blinking or silence the tick.
• Towing a trailer or adding extra lamps: Increased load can alter rates in older thermal systems.
• Weak battery or poor ground: Voltage drops can make flash rates irregular.
• BCM or instrument cluster issue: In vehicles with synthesized audio, a software or module fault can change or mute the sound.

If your tick speed suddenly changes, check the bulbs first; in many cars, hyperflash is a built-in warning that a lamp is out.

Troubleshooting No Click or Constant Clicking

If the clicking disappears—or you hear clicks when the signal isn’t on—targeted checks can narrow the cause before you replace parts.

1. Verify bulb operation: Walk around the vehicle with the turn signal and hazards on to confirm all bulbs illuminate.
2. Check the fuse and flasher relay: Locate the turn/hazard relay in the fuse panel and reseat or replace it if mechanical.
3. Listen for source: Place a hand on the suspected relay or the instrument cluster to feel/hear if it’s the origin.
4. Consider LED conversions: If you’ve installed LEDs, use an LED-compatible electronic flasher or load resistors.
5. Inspect the stalk and canceling mechanism: A worn cancel cam or sticky switch can cause unintended clicks.
6. Scan for BCM/cluster codes: On newer cars, a diagnostic scan can reveal faults in monitored circuits.
7. Test hazards separately: If hazards click but turns don’t (or vice versa), the issue may be in the turn-signal switch or wiring.

These steps address the most common causes—from simple bulb failures to module issues—helping you decide whether a DIY fix or professional diagnosis is warranted.

Quick Facts and Maintenance Tips

A few practical details can help you interpret what you hear and keep the system working reliably.

• Typical blink rate: About 60–120 flashes per minute; hyperflash is usually 120+ and signals a fault.
• Part names to know: Flasher relay, hazard/turn flasher, BCM, instrument cluster chime/buzzer.
• Locations: Under-dash fuse box, steering column area, behind the instrument cluster.
• Costs: Mechanical relays are inexpensive; BCM or cluster-related repairs can be more involved.
• Upgrades: Use LED-compatible flashers to avoid resistors and keep proper monitoring where supported.

Understanding these basics helps you recognize normal behavior and quickly spot when something isn’t right with your indicators.

Summary

The clicking sound from a turn signal is either the mechanical snap of a flasher relay (older designs) or a purposely generated tick from an electronic module or speaker (modern vehicles). It serves as audible confirmation that your indicators are working, and changes in the click—especially rapid hyperflash—often point to a burned-out bulb or load issue. Identifying where the sound originates in your car guides effective troubleshooting and maintenance.