Indicators flickering on Chummy

[PeterN]

Just installed indicators on my 1930 Chummy. 6v system using 10W glass bulbs and 3 terminal electronic flasher relay mounted 5cm from battery. Negative terminal direct to batter neg and positive terminal direct to battery pos.. The indicators flash with ignition only, but flicker with engine running. Any ideas please, and thank you.

[Howard Wright]

Hi Peter

Your electronic flasher unit is probably picking up interference from the ignition leads.  If you are using incandescent bulbs the simplest thing is to change the flasher unit to a electro mechanical one ie not electronic.  10 watt incandescent bulbs are too weak for indicators which should be over 20 Watt.

Cheers

Howard

[PeterN]

Thanks Howard, I might go for a bulb upgrade

[John Cornforth]

Hi Peter

This is very likely to be the electronic flasher unit being upset by interference from the ignition. You may well find that a set of resistive suppressors on the spark plug connectors does the trick. Or, as suggested, use an old fashioned thermal type flasher which will be immune.

Although it's probably academic, the "Road Vehicles Lighting Regulations 1989" calls for a wattage between 15 and 36 for indicator lamps without an approval mark, and that it is "Plainly visible from a reasonable distance". The common filament bulb standard is 21 watts for 12 volt systems. For 6 volts you may also find bulbs intended for motorbikes which are often 18 watts.

[David Stepney]

For what it is worth, when I first had my car, I fitted flashing indicators to it using 6volt 21 watt bulbs (off a well known auction site) and originally an electronic flasher unit. I found that the electronic unit flasher unit flashed far too quickly and replaced it with an electro-mechanical Unit from a VW specialist. The indicators work well, are clearly visible even in bright sunshine, and flash at about 90 beats a minute, well within the 60 to 120 beats per minute specified by law.

[Tony Griffiths]

Having messed about with them on three cars, I've come to the conclusion that -
On a 6-volt system LED bulbs are the best idea - but frequently fail to work due to interference from the ignition and/or dynamo.
One of my cars is fine and runs 6-volt LEDs with no problems, but the other refuses to work at all with the dynamo running. To that car, I've fitted a small motorcycle 12-volt battery and use that to run 12-volt, 21-watt standard bulbs that are very bright.
On 6 volts (or 12) it's a really good idea to wire the indicators - live and neutral - directly to the battery on their own fused circuit. This ensures the maximum brightness; a weak earth on 6 volts is always a concern.
With ordinary bulbs it's better to use a a standard electro-mechanical flasher unit with 3 terminals like this: https://www.classicbulbs.co.uk/products/...asher-unit or, if you need a smaller one: https://www.classicbulbs.co.uk/products/...y-6v-3-pin
The third terminal allows you to connect both a buzzer and a light. Cab buzzers all appear to be 12 volts - but this one is loud on my 6-volt system: https://www.classicbulbs.co.uk/products/...ing-buzzer.
Connected to the same circuit as the buzzer is a tiny but very bright LED light that really easy to fit anywhere - mine is just trapped against the switch panel. https://www.rapidonline.com/KL-6V-60mA-G...gJBnPD_BwE. Or, just search eBay for "grain of wheat 6-volt LEDs".
Rather than the massive switch usually provided with flashers, I've used a small, less conspicuous one: https://www.vehiclewiringproducts.co.uk/...-on-switch.

[Denis Sweeney]

I have a separate set of LED indicators in addition to the original semaphores on Ruby. The LED indicators run on their own separate circuit and have a noise box fitted to let you know they are working. Initially I had no problems and all had been working well, however recently, instead of a regular flashing/beeps they now sound like a morse code machine on overdrive.
Interestingly, on initial driving all seems to be steady but as I travel further the flashing and beeping just becomes more erratic and it is the same each time I travel out in her.
Any suggestions??

Sorted, dodgy earth connection to the suppressor!

[Ruairidh Dunford]

Electronic flasher units only really work well with LED bulbs, in my experience.

Up your bulbs to 21w and buy a suitable thermal type flasher, be aware that most account for the repeater being part of the load - if you don't use one, it will likely flash too quickly...

[Tony Griffiths]

Perhaps switch to a small, separate, 12-volt battery powering a dedicated circuit; use standard, tungsten-type 21-watt bulbs and an ordinary electro-mechanical flasher unit? All the details of where to get the bits are in the comments above.

[David Stepney]

Tony. Why a separate 12 volt battery? A 6 volt system running from the car’s electrical system has worked fine for me over the last five years. I am a great believer in keeping things simple.