Page 2 of 3
Re: Flasher unit or relay
Posted: Sun Oct 30, 2016 6:06 pm
by JOWETTJAVELIN
bmcecosse wrote:NO relays! The can flashers have points and a bi-metal arrangement which heats and cools- so breaking and making the circuit causing the flash. These go on 'for ever'unless perhaps abused by being shorted, or also asked to flash 'trailer' lights. They also won't work with silly LED bulbs----since the current flow is not high enough to heat the bi-metal.
mogbob wrote:No ...you don't need a relay to operate a Lucas FL5 can. It will work quite efficiently on it's own.
Bob
Thanks for the answers. I bought an FL5 so can get on with fitting the winkers. But what are the 3 terminals B,P and L? Also the car has been converted to neg. earth - does it make a difference?
Re: Flasher unit or relay
Posted: Sun Oct 30, 2016 6:32 pm
by IslipMinor
+ve or -ve earth polarity are both the same to a bi-metallic flasher unit, such as the Lucas FL5. If you use an electronic flasher unit they are polarity sensitive.
B = Battery i.e. fused ignition supply
P = Pilot light i.e. the indicator warning light
L = Lights i.e. the feed to the indicator switch
Hope that helps?
Re: Flasher unit or relay
Posted: Sun Oct 30, 2016 6:39 pm
by RussLCV
Just about to say that! Its mentioned earlier I think.
ANy know what electronic flasher relay fits the Minor?
Re: Flasher unit or relay
Posted: Sun Oct 30, 2016 7:02 pm
by IslipMinor
Russ,
Many of the electronic units have the wrong connections to plug directly into the standard Lucas FL5 3-pin socket, but Auto Electric Supplies do one - Pt. No. 140102:
http://www.autoelectricsupplies.co.uk/p ... ategory/35
Works on either +ve or -ve earth by swapping the + and C terminal connections.
[frame]

[/frame]
Re: Flasher unit or relay
Posted: Mon Oct 31, 2016 11:57 am
by RussLCV
Many thanks Richard so will a LUCAS SFB 190 work? There is also a 4 pin with an earth wire and a c terminal for direct to the panel light?
Re: Flasher unit or relay
Posted: Mon Oct 31, 2016 12:42 pm
by IslipMinor
Russ,
From what I can find out, the SFB190 does not have the same connection arrangement as the SL5. Obviously if you do not need it to be interchangeable with the standard SL5 socket, then it can be made to work by wiring it up as required, with the single wire feed to the indicator warning light connected to the same terminal as the feed to the indicator switch.
What do you currently have and what are you trying to achieve?
Re: Flasher unit or relay
Posted: Mon Oct 31, 2016 7:25 pm
by JOWETTJAVELIN
Thanks guys, that's my winter project.
Re: Flasher unit or relay
Posted: Sun Jun 01, 2025 3:02 pm
by Johnrroberts
bmcecosse wrote: ↑Thu Sep 01, 2016 11:47 am
A 'relay' is not a 'flasher unit' -it doesn't flash....... Stick to the normal electrical spec for the vehicle....
Hi bmcecosse, you may be able to help me. I have a Lucas flasher unit with a little bulb in the end of the can. What is the purpose of the bulb?
Regards and thanks
John
Re: Flasher unit or relay
Posted: Sun Jun 01, 2025 3:14 pm
by les
You may have some trouble there, he passed away some time ago. Missed by many

Re: Flasher unit or relay
Posted: Mon Jun 02, 2025 9:36 am
by StillGotMy1stCar
A couple in this thread are no longer with us, IslipMinor has also passed away, another knowledgable chap.
I’ve never seen a flasher unit with a bulb attached, could you post a photo please, we like photos
Regards John
Re: Flasher unit or relay
Posted: Mon Jun 02, 2025 10:31 am
by geoberni
Johnrroberts wrote: ↑Sun Jun 01, 2025 3:02 pm
bmcecosse wrote: ↑Thu Sep 01, 2016 11:47 am
A 'relay' is not a 'flasher unit' -it doesn't flash....... Stick to the normal electrical spec for the vehicle....
Hi bmcecosse, you may be able to help me. I have a Lucas flasher unit with a little bulb in the end of the can. What is the purpose of the bulb?
Regards and thanks
John
As already advised, some of those posting more than a few years ago are no longer with us.
I've never seen or heard of any Indicator Flasher Unit with an integral bulb.
Since flasher units are invariably located out of sight, it would make little sense to include such a feature.
Please post a photo and detail any markings you can see on the device.
Posting a photo is done by following the instructions on the 'Attachments' Tab, below where you write a comment.
Once attached, clicking [Place inline] will include it in whatever you've written, at the point where the Cursor was last positioned.
Re: Flasher unit or relay
Posted: Mon Jun 02, 2025 11:18 am
by Chief
We're also presuming it's an electrical bulb, might be a Tulip or Daffodil
Definitely need a photo as even google images etc. finds no flasher units with bulbs.
Re: Flasher unit or relay
Posted: Thu Jun 05, 2025 3:34 pm
by Johnrroberts
StillGotMy1stCar wrote: ↑Mon Jun 02, 2025 9:36 am
A couple in this thread are no longer with us, IslipMinor has also passed away, another knowledgable chap.
I’ve never seen a flasher unit with a bulb attached, could you post a photo please, we like photos
Regards John
Hi all - apologies, I'm a new starter but old tinkerer and in my ninth decade now. I sincerely doff my hat to those who have gone before - they represent the wealth of our knowledge if someone knows to ask them. Still getting used to working this computer thing - the one I usually use has funny red stuff running through it and doesn't start well on cold mornings. Photo is attached - no flowers though.
Re: Flasher unit or relay
Posted: Thu Jun 05, 2025 4:04 pm
by Chief
That's a curious thing, sorry I can't help you with it - nothing at all comes up on web searches for any of the numbers on it.
If no one here ends up being able to help, then one forum I did come accross in my searches was the Australian Rolls Royce forums talking about different Lucas relays, it's possible they may have more clues to Australian made Lucas products:
http://au.rrforums.net/cgi-bin/forum/di ... ?pg=topics
Some Australian owners also belong to this Minor forum:
https://www.morrisminorforum.com/
And finally, there's this parts place in Syndey which may be of use to know in case you need spares anyway:
https://www.minormagic.com.au/
Re: Flasher unit or relay
Posted: Thu Jun 05, 2025 4:26 pm
by geoberni
Well that is certainly a new one on me.
I've never seen anything like it, either the bulb or the 2 lugs on the top of the canister.
I'm thinking that this may be a unique product for Australia, given that is where it was made.
I've looked back at various old catalogues for Joseph Lucas Ltd, England, and can find nothing like it.
But some of the overseas subsidiaries, like Australia, were large enough to have their own development teams; the Australian one was noteworthy for battery technology in particular.
The only possible/practical reason for the bulb is to give an indication that the flasher unit is working.
There must have been one or more vehicles on the Aussie market where it was worth Lucas developing such an unusual unit for a customer.
But I don't believe it would have been for a CKD kit Morris; although there was a great deal of local content for locally assembled Morris cars.
Re: Flasher unit or relay
Posted: Thu Jun 05, 2025 4:48 pm
by svenedin
What an interesting thing. Zooming in on the picture it looks like the two contacts are actually round pins. Is that correct? I am guessing the flasher can fitted in a socket behind the dashboard and the bulb protruded through. Rather clever actually.
Stephen
Re: Flasher unit or relay
Posted: Thu Jun 05, 2025 4:52 pm
by geoberni
svenedin wrote: ↑Thu Jun 05, 2025 4:48 pm
What an interesting thing. Zooming in on the picture it looks like the two contacts are actually round pins. Is that correct? I am guessing the flasher can fitted in a socket behind the dashboard and the bulb protruded through. Rather clever actually.
Stephen
Certainly unusual, but it would rely on an interference fit of the 2 lugs into receptacles. Unless some further bracket arrangement....
I have doubts as to the practicality.
I'd love to find out more about it.
Re: Flasher unit or relay
Posted: Thu Jun 05, 2025 4:53 pm
by svenedin
Re: Flasher unit or relay
Posted: Thu Jun 05, 2025 5:09 pm
by Chief
svenedin wrote: ↑Thu Jun 05, 2025 4:53 pm
Aha!!
Good find, of course the next question is, What did it actually warn you about, I mean was it just the indicators not working or was it linked to some other things.
Also, is this the worlds first engine warning dashboard lamp

Re: Flasher unit or relay
Posted: Thu Jun 05, 2025 5:44 pm
by svenedin
Chief wrote: ↑Thu Jun 05, 2025 5:09 pm
svenedin wrote: ↑Thu Jun 05, 2025 4:53 pm
Aha!!
Good find, of course the next question is, What did it actually warn you about, I mean was it just the indicators not working or was it linked to some other things.
Also, is this the worlds first engine warning dashboard lamp
Good question!
Stephen