Vintage car, new indicators and relay very erratic when engine is running

[stevefizz]

Restoring a 1938 vauxhall DX positive earth 12v

Installed indicators and a relay works fine with the ignition on but flash very erratic when the engine is running

12V ELECTRONIC INDICATOR FLASHER RELAY POSITIVE EARTH GROUND 2 or 3 PIN OPTIONS | eBay - http://www.ebay.co.uk/itm/12V-ELECTRONIC-INDICATOR-FLASHER-RELAY-POSITIVE-EARTH-GROUND-2-or-3-PIN-OPTIONS-/181922801187?hash=item2a5b71a623:g:U-4AAOSwbwlW~8cT

do i need a solid sate voltage regulator
do i have a fault somewhere
have i wired it up wrongly
or something else

Thanks
steve

 

[Wilko]

Hi Steve and Welcome to the Forum.
It sounds like flasher is not happy with its power supply, doesn't it? You could try a temporary direct connect to your battery - both + and - . The battery will naturally smooth any chatter from dynamo. If It works then with the engine running then can try to improve the power wiring to the flasher perhaps.

Edit - be careful with the +ve earth as the new flasher may not cope with that !
Edit of Edit - just read the link, flasher is good

 

[stevefizz]

Thanks, sounds like a plan. I get an in-line fuse and try it tonight

 

[stevefizz]

Still the same. the plot does thicken though. i had the dynamo cables the wrong way round. now occasionally the ignition warning light stays on when i turn the ignition off.

 

[PEG]

Hi,have you checked the dynamo/regulator for correct operation? If the flasher unit works OK with plain old 12v,then it sounds like the engine running,is either causing the voltage to be pulled down,or raised.

A simple check with a multimeter at the flasher unit,when ignition on,and then with engine running,should assist.

I've just had a quick look at me bookcase,and i still have some paperwork for the dynamo on an Austin Ascot Light 12/4 that i owned.

I remember doing a fair bit of "flashing" the field,and glass papering regulator contacts,in order for it to keep the battery semi happy.