Last week I changed the odometer cable on my Honda Activa scooter which involved in removing the connection to my side indicator and headlamp. After finishing off the work I did the connection to indicator and headlamps and checked them.But since then I am facing strange issue with my blinkers their blinking frequency changes with the speed of my scooter i.e they blink faster at low speed but normally when riding above 20 kmph speed. I thought it could be a loose connection so I reopened the cover and inspected for the connection but they seem to be all ok and also the battery voltage is at 12v which is the expected value.Any suggestions what else needs to be checked

[EDIT]: The blinkers blinks faster when the engine is on(blinking from alternator) but blinks normally when engine is off and transmission is on(drawing current from battery)

  • 1
    On some cars, the faster blinking frequency means that some indicator bulb isn't working anymore and should be replaced. But on a cheap scooter? Could be something else. Anyway, battery voltage should be 12.8V at rest, and even more (13.5-14.5V) when charged. Is the phenomenon binary (i.e. it has two distinct blinking frequencies) or continuous (i.e. the blinking rate goes down continuously as speed goes up)?
    – juhist
    Commented Sep 4, 2017 at 13:42
  • its binary.it has only 2 states
    – DhKo
    Commented Sep 4, 2017 at 17:30
  • All the bulbs are fine
    – DhKo
    Commented Sep 4, 2017 at 20:40
  • 3
    It suggests to me (but not confidently enough for an answer) that the alternator/dynamo/whatever is on the way out. At low speeds, the battery is not being charged enough and the fault-system thinks a bulb is blown -- and indicates that by increasing the blink frequency. At higher speeds, the voltage is correct and all is well. Commented Sep 6, 2017 at 9:48
  • @AndrewLeach I think the 12V battery voltage, if accurately measured with a multimeter, supports your theory. The voltage should be higher. The OP didn't specify if that's the resting voltage or the idle charging voltage, but if it's the idle charging voltage, it's definitely way too low. So I think there's enough evidence for an answer.
    – juhist
    Commented Sep 6, 2017 at 11:08

1 Answer 1


IMPORTANT - Is this only happening with one light? Or all?

In most vehicles, the blinker circuits are fairly simple. However, on scooter and motorcycles they’re (generally) much simpler. For example, on my bike there are really only 4 sets of components:

  1. Voltage Source
  2. Switch
  3. Flasher Relay
  4. Lamps

Due to this simplicity, I don’t think that there are many bike that have a system to “warn you” that a lamp is going, rather, this is a natural function of the relays design.

The relay frequency is affected by the amount of resistance on a given circuit. Less resistance = faster blinking because voltage can get to filling the caps faster. More resistance = slower blinking.

I see 2 possible situations depending on if the problem is whole system or just one lamp:

One Odd Lamp

Bad grounding (earth or negative), incorrect wiring, wrong bulb. One of these type of things. You really just have to follow the circuits and look everywhere for a problem.

Problem with all blinkers

In this case - you really need to inspect the whole system, both running and off! If your voltage regulator/rectifier has failed this could create a lot more expensive problem, not to mention be a risk to whoever is operating the scooter!However, it’s not common for the VR/R to fail like this. Usually this will just break the circuit completely.

That said, if the problem is system wide, you’re looking at voltage source or flasher relay as the answer. Of those 2 I’d say replace the flasher relay. It could be coincidence that or failed the same time as repairing it, you could have accidentally done something that damaged it... regardless, those are the only options really. Other than that, you’re looking at pulling the whole thing apart and carefully diagnosing everything.

Also, it may not help, but try disconnecting or undoing whatever recent work you did on the scooter. It is possible that a faulty or cheaply manufactured part could cause the voltage drop needed to mess that up.

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