Indicators flickering on Chummy

[Tony Griffiths]

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.

I agree, keep it simple whenever possible. But, why 12-volts? Because of all the problems outlined in my previous post. LEDs need a perfect-as-possible earth and often refuse to work due to interference from the engine and stop lights, etc. Standard bulbs on 6 volts are often not bright enough to be seen in bright sunlight. Of course, some 6-volt systems running LEDs do work without problems - I have one car like that, and its 5-watt LEDS have been measured as bright as the 12-volt, 21-watt units on another car. 
Instead of a 12-volt battery, to get 12-volt brightness you could use a 6 to a 12-volt step-up transformer, like this (or search eBay for "WaterProof 6V to 12V 3A 36W Step Up DC/DC Power Converter Regulator UK) but, the unit is limited to an output of 3 amps, and, as two 21-watt bulbs draw 3.5 amps it's probably on the margin of not working or, if it does, might fail prematurely? Of course, if the car is "LED proof" it would work with LED bulbs.
Indicators on an A7 can be a problem with no off-the-shelf solution - so I've summed it up as far as possible here: http://www.lathes.co.uk/austin-7-indicators 
No doubt I've omitted something, so comments, contributions and corrections are most welcome.

[PeterN]

Many thanks for the interest and advice. As a first move I'll fit an electromechanical relay from LED Bulbs and keep the glass bulbs. If that fails , I'll put back the old relay and change to LED'S. More later, but thanks again. Tony's article is a good read.

[Barry Townsend]

I had identical problem with my RN. Supressor caps solved it. Up the wattage of your bulbs or change to LED's

[PeterN]

Just to draw a line under this, with thanks for the advice, I substituted the electronic relay with an electromechanical one and am now flashing happily.

[Denis Sweeney]

Sorry for resurrecting this thread but I somewhat prematurely claimed to have fixed my problem of erratic LED indicators.
As noted earlier on this thread I have a completely separate set of indicators all components from DRC which include LED indicators, switch, flasher unit, sound unit, suppressor and separate fuse.
With the engine off the system works perfectly, with the engine running it still works perfectly ……. that is until about 20 minutes into the trip and the system turns into a frantic morse code message and carries on that way until we switch off the ignition.
Leave her standing for half an hour, switch on and everything is working again as normal until she gets warmed up again.
A member at the local A7 club gave me some gadgets the name of which I cannot remember that clip over the wires local to the flasher unit to help cure the problem but these made no difference.
Need to get this sorted pdq.
Any suggestions gladly received
Cheers

[John Cornforth]

Hi Denis

I recommend you try four resistive ignition suppressors of the type that fit onto the spark plugs.

[Dave Wortley]

I changed to 12v from 6v for the indicators only because I had a small 12v battery from my late father-in-law’s stairlift. They are definitely sparkier than 6v.
(Also I am a tight-wad.)

[Tony Griffiths]

Presumably, you are running a 6-volt system and on many cars, these can be a nightmare to get working properly. In a previous comment, I wrote that one of my Sevens works perfectly with 6-volt LED bulbs and an electronic flasher unit but another does not - and nothing would persuade it to work with the dynamo charging. Hence, I'd recommend what I and others have done, change to a separate 12-volt system powered by a small 12-volt motorcycle or similar type of battery. You might find that this works perfectly with your existing electronic flasher unit and LED bulbs (your 6-volt bulbs might even be a "dual-voltage" type and still work) - but, if interference from the ignition circuit or dynamo is still having a detrimental effect (as it was on my 'problem' car) just change to ordinary 21-Watt bulbs and a mechanical flasher unit. It will then work perfectly with very bright flashers. I've summed up the whole saga as far as possible here: http://www.lathes.co.uk/austin-7-indicators
BTW I now have David's car with the stairlift battery. Goodness knows how old that battery is - probably 25 years at a guess - but it still works perfectly and the other day, having left the indicator on all night, they were still flashing in the morning. Another note: our Ruby runs a 12-volt system with LED bulbs - but powered not by a separate battery, but a 6-volt-to-12-volt step-up transformer. This too has proved reliable and the flashers very bright.

[Denis Sweeney]

Fingers crossed I think the problem may have been resolved.
Having contacted CDRC their advice was to locate the flasher unit as far away from the coil as possible, if this did not work put a suppressor on both the coil and dynamo.
My flasher unit is located under the dash and short of running it to the rear of the car it was difficult to get it much further away and so went for the additional suppressors.
With these in place I took Ruby for a 45 minute run yesterday and the indicators never skipped a beat. Previously the system would have gone awol after just 15 to 20 minutes so long may this last.
However my understanding of all things electric is limited and through my lack of knowledge it raises the question to me at least, could there be an issue with the coil and dynamo to create the interference in the first place??
Cheers and thanks for the repiies

[Tony Griffiths]

"....could there be an issue with the coil and dynamo to create the interference in the first place?" The dynamo and ignition do provide the necessary interference, but do you mean that there might be a fault with the systems? This could be the case, as one of my cars an all-LED-bulb-electronic-flasher system works perfectly but on another, fitted at the time with the same models of distributer, coil and dynamo, it didn't. I did try swapping over the coils to see if it would make any difference, but it didn't and I was too busy doing other stuff to take it further.