Why do car turn signals only work sometimes?
Intermittent turn signal failure is typically caused by a loose wiring harness, a failing multi-function switch in the steering column, or a faulty gear selector position switch if signals only function while parked. These electrical glitches leave drivers without working blinkers or hazard lights while on the road, creating an unpredictable and hazardous driving condition.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
Found another way around this?
Share your steps and trade-offs so fellow engineers don't have to reinvent the wheel. No account required.
- 1Checking front harness ground pointsDid this help you?
- 2Considering replacing the combination switch or looking for frayed wiringDid this help you?
- 3checked the fusesDid this help you?
- 4tried to replace the hazard switch under my dashDid this help you?
- 5check the multifunction switch on the steering columnDid this help you?
- 6check the grounds around the steering column or under the dashDid this help you?
- 7Checking or replacing the flasher relay near the tongueDid this help you?
- 8replace both bulbsDid this help you?
- 9check the wiringDid this help you?
- 10checking the blinker relay, bulb sockets, and wires under the seatDid this help you?
- 11replacing parts randomlyDid this help you?
- 12using a multimeter to test power and trace circuitsDid this help you?
In their words
Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.
“I have brake lights, hazards and running lights, but turn signals on both ends of the trailer are inop.”source ↗
“My turn signals and hazard lights suddenly stopped working.”source ↗
“So far, I haven't found anything obviously wrong.”source ↗
“Hyundai Santa Fe sport 2017 both front blinkers intermittent along with driver side fog light”source ↗
“She describes it as working when it wants to.”source ↗
“randomly yesterday my car did not have turn signals or hazards when i was driving. When i pulled into a parking lot and put it into park i noticed they started working as soon as it is park but no other gear.”source ↗
“I left car on and looked at both on that side and they were still working just faster”source ↗
“They may be after market, bought the truck from my brother in law 4 years ago so now would be a weird time for them to start acting funky as I haven’t done any to big to it besides normal maintenance since I got it, so ig they’ll go out soon”source ↗
“on my 79 yamaha xs750 i just got it as a project and one of the tail lights works but why is it when i press the blinker button left it just stays on but if i press it right it turns off”source ↗
Where this came up
People with this problem also raised
- 6Why is my car showing random dashboard warning lights?
- 2Dashboard lights and ABS lights flashing when using turn signal
- 10Why does my car battery warning light flicker on and off?
- 4High beams don't work even though fuses, relays, and bulbs are fine
- 26Intermittent car hesitation with no trouble codes
- 2Why does my car die when I turn on the headlights?