This happens randomly, and in short bursts. Seems to be coming from the fuse/ indicator relay area under the dash. No evidence of anything happening anywhere. Thought it was the indicator relay going mental so I replaced it. No change. Typically happens when sitting quietly at the lights.
Gerry
Frenzied ticking at right knee.
Moderator: RichardW
- Panjandrum
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I have seen this problem lots on AXs and Peugeot 106s - it might be the same as on yours. Its the indicator switch. The flasher unit operates on a different switch to the supply to the lights and sometimes this switch closes when the lever is not quite centred. If you mess around with the indicator lever you may find that the noise stops. If so thats the porblem.
I am describing here what I learned with this problem in a 1995 Xantia, probably it is similar on your car.
Although triggered by leakage on the indicator switch contacts, the flasher unit itself has a design fault that makes the problem much more likely to occur.
If you analyse the circuit inside the flasher box, you will see that the component values do not match those recommended by the manufacturer of the ASIC at the heart of the unit. This makes the flasher unit much more sensitive to switch leakage than it should be.
You may find that an after-market flasher unit will not have this problem.
I fixed it by opening up the flasher unit and solderfing in an extra resistor to restore the design to the correct values.
Although triggered by leakage on the indicator switch contacts, the flasher unit itself has a design fault that makes the problem much more likely to occur.
If you analyse the circuit inside the flasher box, you will see that the component values do not match those recommended by the manufacturer of the ASIC at the heart of the unit. This makes the flasher unit much more sensitive to switch leakage than it should be.
You may find that an after-market flasher unit will not have this problem.
I fixed it by opening up the flasher unit and solderfing in an extra resistor to restore the design to the correct values.
The data sheet for the ASIC can be found at:
http://www.atmel.com/dyn/resources/prod ... oc4727.pdf
The component that sets the sensitivity to switch leakage is R2, which is physically mounted under the relay coil.
On the notes I made when I inspected the flasher from my previous car, the value fitted was 100 ohms, rather than the 1.5..2.2k ohms recommended.
I just opened up the flasher on my current car, and the component fitted for R2 is 1k ohms, just a little low.
According to the data sheet, with the correct resistor fitted, the flasher should stay silent with a leakage of up to 5k ohms.
I think on my previous car I fitted a 2.2k resistor for R2, and never had the problem until I sold the car.
regards,
Mike
http://www.atmel.com/dyn/resources/prod ... oc4727.pdf
The component that sets the sensitivity to switch leakage is R2, which is physically mounted under the relay coil.
On the notes I made when I inspected the flasher from my previous car, the value fitted was 100 ohms, rather than the 1.5..2.2k ohms recommended.
I just opened up the flasher on my current car, and the component fitted for R2 is 1k ohms, just a little low.
According to the data sheet, with the correct resistor fitted, the flasher should stay silent with a leakage of up to 5k ohms.
I think on my previous car I fitted a 2.2k resistor for R2, and never had the problem until I sold the car.
regards,
Mike