Turn signal works sometimes but not consistently

Symptoms

• Turn signal works fine some days but not others
• Wiggling the wiper stalk or bumping the car sometimes fixes it temporarily
• Issue seems worse in cold or wet weather
• No consistent pattern to when it works or doesn't

Likely causes

• CommonLoose or corroded bulb socketA marginal connection can work intermittently depending on vibration or temperature.
• CommonWorn turn signal switch on the steering columnThe switch mechanism can wear unevenly, causing inconsistent contact.
• PossibleCorroded connector in the wiring harnessA connector partway along the circuit can develop intermittent corrosion issues.
• PossibleTemperature-sensitive component (expands/contracts affecting contact)Some intermittent electrical faults only show up in specific temperature ranges.

What to do

1. Note any pattern to when it works and doesn't, such as temperature, time of day, or after hitting bumps.
2. Check and clean the bulb socket for the affected light, since this is a common source of intermittent connections.
3. Try wiggling the turn signal stalk gently while the signal is on to see if it affects the light.
4. Inspect accessible wiring connectors along the turn signal circuit for looseness or corrosion.
5. Have a shop use a scan tool or wiggle test while monitoring the circuit if the pattern isn't obvious.
6. Avoid ignoring an intermittent fault, since it typically progresses to a complete failure over time.
7. Replace the turn signal switch if it's identified as the source through steering column testing.
8. Keep notes of exactly when the fault occurs to help a shop diagnose it faster, since intermittent issues are harder to catch.

Tools and parts

• Flashlight
• Electrical contact cleaner

When to call a pro

Intermittent electrical faults are often best diagnosed by a shop that can monitor the circuit while wiggling components to catch the fault in action.

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