Hazzard warning lights ?

[Peter Wade]

Hi Chaps.

No doubt it's been covered before but can't find anything on the forum. 

After a breakdown over the weekend and having no hazzard warning lights on a very busy road have decided to install hazzards lights, so my questions are:-

1. I have LEDS all round are the hazzard warning light kits from the usual suspects compatible?.

2. How difficult are they to Install on a scale of 1 being simples 10 being very difficult. 

Forgot to mention my vehicle is a TR4A.

Kind Regards 

Peter W

[RobH]

Here are a couple of  previous discussions Peter.

an alternative or additional measure is to carry a couple of these:

https://www.amazon.co.uk/Waterproof-Triangles-Emergency-Floodlight-Assistance/dp/B0CT8X2D8G/ref=sr_1_6?crid=3CEPUTVF6WE7E&dib=eyJ2IjoiMSJ9.rooRRxi2MMvckC-DsAE8KXRlyhIJc1a99qySB97l3Vey-VLcw7BsMq9mpZIR9X1zQ8DEH7gevbXlYO20AC-46ZLMz8gMIwVnFTD_nnQ__WkVgKYNQqkL68zkZMKYlZoRK7AOmOnPTtl-t6Tf3HYft4vUEm7_SfV4skUveZ3Hrph1e66qSfkfX2eHeQO9LOECarvr-yDOsTyvEiIi1NUOJ_iVCLjW0OLtuoIeMKern5k.c-7w2ow0Lh3czavVlLsjT87WVtPdapzpUNzJCgXO_lQ&dib_tag=se&keywords=car+hazard+warning+lamps&qid=1753870560&sprefix=car+hazard+warning+lamps%2Caps%2C1027&sr=8-6

 

 

 

Edited July 30, 2025 by RobH

[Chris Hale]

Peter

Its probably a 5, just take your time and identify where you want to put everything and where you have to run extra wires to

I used one of these  https://www.ebay.co.uk/itm/185648401758?_skw=lucas+hazzard+light+switch&itmmeta=01K1DHBWCBSFG9WHP1HSAMNBY1&hash=item2b3981cd5e:g:gNEAAOSwKmRjaNlv&itmprp=enc%3AAQAKAAABAFkggFvd1GGDu0w3yXCmi1dcx4pN85Pi7eIdB9CQYIdORaT2KLWa%2FpJ3Ifzbhp25yunK%2Bz7gmZMr2rGEu2KQqe7HlA0BIEtMsPZH7DZKcdHs016JV%2Fio3OSZIkfGRyQ%2FXoxuTd6nTk%2FrhH8NKtKFkO75ZxdGMw%2BqwvSbCDUYvNHzBFAEE1mkBRM1cx8zm2GMIabiEDtzHCeiLx0o9oEdkfbUuJFprjxY9HCdX9wITDGDQevluJM0mfjd7N8Gia8zDhrq5CLJbWVfpF%2BkCU1Sxwn6jgQSgkqi%2BjuQWVoMEJuKlG%2F0f3A%2BrXfTaQkK30IS2Y2gLDKSFwmNxvTcKRBmTS0%3D|tkp%3ABk9SR7rGr7GLZg on my 6 and have one to install in my 4A
 

Due to lack of room where I wanted to site the switch I did not use there mounting bracket separated the switch and relay and mounted the relay next to my indicator relay which meant making up a loom from the switch to the relay. Pretty simple job 

Edited July 30, 2025 by Chris Hale

[RobH]

If you are going to buy a kit Peter,  best to check with the supplier whether it will work with LED lamps if it doesn't specifically state that in the ad. 

The difficulty depends on whether or not you are experienced with doing wiring. 

[Lebro]

With LED lamps you dont need an extra flasher "relay" just a switch.

See the two articles above which Rob posted.

Bob

[Peter Wade]

Hi.

Many thanks for all the replies, well at least I'm now clear on the Lucas kit I didn't realise the relay was mounted within the switch so I'm OK with that, I'm just concerned that it is LED compatible I'm sure one of you guys will let me know or weather I have to change the relay I fitted when I changed to LED's.

Cheers Guys

[RobH]

Peter, the Lucas SBF300 and equivalents are available from a lot of different suppliers most of whom have an installation instruction sheet  - none of them say it is LED compatible so I would assume the flasher unit inside is for normal bulbs only. 

[Peter Wade]

Chaps,

I'm clear on the way forward as I have LED's and have already replaced the flasher relay for an electronic one which came in the LED kit I purchased from Classic LED's I don't need another relay so just require a hazzard switch which I've ordered.

Cheers All.

Peter W

[Lebro]

Good man !

Bob

[PodOne]

Apologies for hijacking this thread for TR4 retro fitting Hazard light switch but I'm in the same boat with regard to my 1969 TR6.  It's the one thing I should have done when I rewired the car.

I bought one of these https://www.moss-europe.co.uk/en-gb/hazard-warning-light-kit-gss159 from Moss some time ago but haven't got around to fitting.

Question I have fitted LED's all round and LED Flasher unit all bought from Classic LED lights will the Moss switch work? Any wiring diagrams appreciated.

Thanks

Andy

[RobH]

I believe the Moss switch is the same as the Lucas one Andy though it is the unbranded generic version.  I have looked at many sources for that and I don't think any say they are suitable for LEDs.  It's the flasher unit in the switch that needs to be compatible,  it might be  but they just don't say.  It ought to be  relatively easy to swap that for the correct type if it doesn't work but it might not fit in the switch itself as the original does (item 5 here).  

This one might fit though :

https://www.feked.com/genuine-lucas-led-compatible-12v-two-pin-indicator-flasher-unit-adjustable-frequency.html

 

As you can see elsewhere on this thread, you don't actually need to have a separate hazard flasher unit anyway.   

[PodOne]

Hi Rob

Thanks for your post. I'm no electrical wizard!

My understanding is that the Moss switch cuts the supply to the LED flasher fitted to the car and uses the flasher in the Moss switch which may or may not work with LEDs.

Are saying there is actually no need for the flasher within the Moss Switch if so could it still be used minus the flasher using the LED compatible one already fitted in the car. Which wiring diagram would I follow?

Looking at the Lucas LED compatible flasher for a £5 its worth a go as I have the Moss switch already if so its likely the easier option?

Thanks again

Andy

[RobH]

The various circuits to use the existing flasher only, are in the linked posts higher up the thread Andy and use different switches. I don't know whether the Moss switch used alone would be suitable for that. I doubt it as I don't think it has enough 'poles'. 

As you say, since you already have the Moss ones It would be easiest just to use them as intended and swap the internal flasher unit if necessary. (Note what the seller says about those alternatives, for polarity of the connection)

[PodOne]

Thanks Rob

Flasher ordered I'll update regarding its fitment to the Moss switch and use the supplied Moss wiring instructions.

If it wont fit in the switch I can always mount it remotely.

Andy

[heckler]

Andy  I have the Lucas equivalent of the moss one . The electronic flasher for the LED’s I purchased doesn’t fit inside  the housing so sits just outside.  Chris.

[PodOne]

Thanks Chris

[Peter Wade]

Hi Chaps.

Update from the instigater of this topic, installation of hazard warning lights success all working as they should, many thanks to all with help and instructions all you guys are so helpful.

Cheers All

Peter Wade

[John Morrison]

Peter, 

what did you actually fit in the end?

John

[Peter Wade]

John.

I used the Lucas hazard switch SBF300 removed the relay and put and electronic one from Classic LEDS, put a diode from the existing indicator relay and one on each side of the indicator switch (right side & left side), I'm not very good with vehicle electrics but just took my time and tested as I went along, so pleased with myself.

 

Cheers All

Peter Wade

 

[PodOne]

Hi all

Thought I would update this thread to confirm the Moss switch/flasher will not work with LED lights. https://www.moss-europe.co.uk/en-gb/hazard-warning-light-kit-gss159

As recommended by Rob you need to replace it with https://www.feked.com/genuine-lucas-led-compatible-12v-two-pin-indicator-flasher-unit-adjustable-frequency.html

It can be made to fit with a bit of surgery to the case not pretty but avoids having to extend the wiring and is hidden under the dash. After an afternoon work I now have hazard lights 😃

Andy