* Turn Signal Switch: This is the most common culprit. The switch is a mechanical component that can wear out, get internally shorted, or simply have a bad connection. Internal contacts can become corroded or broken, preventing the appropriate electrical signal from reaching the flasher unit. This is the first place to suspect.
* Turn Signal Flasher Unit: While you've checked fuses, the flasher unit itself can fail. It's a small, usually bi-metallic, device that controls the flashing rate. A faulty unit may prevent the signals from working at all, or cause erratic flashing behavior.
* Wiring Harness: A break or short in the wiring between the switch, flasher unit, and the lights is also possible. This is more difficult to diagnose and requires tracing the wiring. Look for damaged insulation, corrosion, or broken wires, especially near the steering column and around the undercarriage where wires are prone to wear.
* Multifunction Switch (Combo Switch): The turn signal switch is often integrated into a larger multifunction switch that also controls wipers, headlights, and other functions. A fault within this larger assembly could impact the turn signals while leaving other functions working.
* Hazard Switch/Wiring: While your hazards work, a problem *within* the hazard switch circuit *could* interfere with the turn signal circuit if there is some shared wiring or a common ground issue. This is less likely but possible.
* Ground Issues: A poor ground connection somewhere in the turn signal circuit can prevent the lights from functioning. Poor ground connections can cause intermittent issues, sometimes only affecting certain functions.
Troubleshooting Steps:
1. Inspect the Turn Signal Switch: Try wiggling the turn signal lever; if the signals flicker, the switch is a prime suspect.
2. Check the Flasher Unit: Locate the flasher unit (usually under the dash) and try replacing it with a new one. It's inexpensive and easy to swap.
3. Visual Inspection of Wiring: Carefully inspect all wiring related to the turn signals, looking for any damage or corrosion.
4. Test the Bulbs: Though unlikely if other lights work, ensure all your turn signal bulbs are functioning.
5. Use a Multimeter: With a multimeter, test for voltage at the switch, flasher unit, and bulbs to trace the circuit and pinpoint where the signal is interrupted. This requires some electrical knowledge.
If you're not comfortable working with car electronics, taking the car to a qualified mechanic is recommended. They have the tools and experience to diagnose the issue accurately.
