Fitting hazard warning lights - correct wires?

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Oldmogman
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Fitting hazard warning lights - correct wires?

Post by Oldmogman »

Has anyone fitted a hazard light switch kit from ESM or Brum Minor Centre/David Manners Group (it has six leads and a built-in flasher module) who could share their experience?

I’ve identified what I think is the correct live feed source and wires under the dash, but want to check before I start fitting!

1. I see there is a spare connection on the fusebox that provides permanent power, which I assume this is the ‘unswitched point’ referred to in the instructions for the connection of the purple wire in the kit. Is this correct?

(The instructions also offer the alternative of connecting directly to the ‘battery feed terminal’, but I’m not sure what that is.)

However, I doubt that, with the unit mounted under the dash, the purple wire is long enough to reach the fusebox, and will have to be lengthened. Was this your experience? Or does it mean the live feed should be picked up somewhere else?

2. There are two thin, bright green wires under the dash, which I see connect with the loom for the indicator switch. One has power when the ignition is turned on (the other does not). I assume this live one is the one that needs to be cut and each end attached to one of the green/purple wires in the kit?

3. I have also identified the under-dash wires for the left (green) and right (green/white) indicators under the dash, and assume I can connect to the existing connector blocks with a bullet connector?

Thanks all!
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geoberni
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Re: Fitting hazard warning lights - correct wires?

Post by geoberni »

Not that kit, I fitted an original 1970s one I had in the garage.
But basically, with the different systems fitted and changed made over the years, you have to be a little bit adaptive to your vehicle standard.

I have no idea what the wiring is like behind your dash, my car is on the DB10 Relay so different from latter cars.

‘battery feed terminal’ is any place which has a permanent live at it.
2. There are two thin, bright green wires under the dash, which I see connect with the loom for the indicator switch. One has power when the ignition is turned on (the other does not). I assume this live one is the one that needs to be cut and each end attached to one of the green/purple wires in the kit?

There should not be 2 green wires where 1 is permanent live and 1 is switched.
Green is the colour used for switched supply, Purple is permanent supply.
What on earth do you mean by "the one that needs to be cut and each end attached to one of the green/purple wires in the kit?"
Why do you think you need to connect any 'live' switched or otherwise, currently in the car, to green/purple wires?

The 6 cable attached to your switch will be
1x Purple - Permanent live
1x Black - Earth
4x Green with trace colour, Most likely 2x Green/White, and 2x Green/something - These are for the 4 indicator lines
I have also identified the under-dash wires for the left (green) and right (green/white) indicators under the dash, and assume I can connect to the existing connector blocks with a bullet connector?
Unless someone has been messing around with your wiring, there is no such thing as a a solid Green for Left Indicators. All Indicators are Green/something.

Green/White and Green/Red are the standard colours for R/H and L/H indicators respectively.


So to reiterate:
Purple - Battery/Permanent Live
Black - Earth
Other 4 cables connected into the 4 indicator lines. How you do this will depend what existing connections are available to you to break into. In my case I had the DB10 terminals to connect to.

Simple as that.

See this top where I posted the diagram for my layout: viewtopic.php?f=11&t=72067&hilit=hazard ... 90#p654490

I omitted the Black (Earth) cable.
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Oldmogman
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Re: Fitting hazard warning lights - correct wires?

Post by Oldmogman »

Hi Geoberni

Thanks for your response.

My car is a ’66 model and the wiring is original.

My reference to the wire that needs to be cut is taken from the instructions, which read: ‘Cut the wire that goes from the ignition switch to the live terminal (usually marked ‘B’) on the existing flasher unit. This terminal is live only when the ignition key is on.’

The wire on the centre connector of the flasher unit is the same bright green as the ones I identified under the dash, while the ones either side are green/red and solid green.

However, you are right about the green indicator wire under the dash – I couldn’t see properly in the gloom but it is actually green/red or maybe green/brown.

As for my reference to the connection to the live wire, this also comes from the instructions: ‘Connect one green/purple wire to the wire you have just cut, which comes from the ignition switch. The second green/purple wire [should be connected] to the cut end going to the flasher unit.’

So it would seem that the only question might be have I found the correct live wire from the ignition switch?

But surely the fact that the one connected to the flasher unit is the same bright green as the one under the dash must mean it is goes from the ignition switch to the flasher unit?
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geoberni
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Re: Fitting hazard warning lights - correct wires?

Post by geoberni »

I think I have this now.
You said
2. There are two thin, bright green wires under the dash, which I see connect with the loom for the indicator switch. One has power when the ignition is turned on (the other does not). I assume this live one is the one that needs to be cut and each end attached to one of the green/purple wires in the kit?
Which I took to mean 1 was Live on the Ign Sw, the other was live all the time.
What I now think you meant was 1 was live on the Ign Sw, the other was dead all the time presumable because you had disconnected it to check.
But they should not be 2 Bright Green, 1 should be 'Regular' darker Green, the one that is the switched supply, the other should be Light Green and that is the one going to your tell tale lamp on the steering column switch. That'll be the one you have called Bright Green.

So DO NOT CUT THE BRIGHT GREEN CABLE.....

Without having seen one of these Units, what I believe from your description is that the
Cut the wire that goes from the ignition switch to the live terminal (usually marked ‘B’) on the existing flasher unit. This terminal is live only when the ignition key is on.
Connect one green/purple wire to the wire you have just cut, which comes from the ignition switch. The second green/purple wire [should be connected] to the cut end going to the flasher unit.
is intended to interrupt the supply to the Regular Flasher, to prevent hazard Lights and an Indicator being switched on at the same time.
This apparently was a feature of the original Lucas SFB300 design.

What you have is basically this diagram. Your switch assembly with it's 6 wires is the area within the red line
Hazard Unit.JPG
Hazard Unit.JPG (56.58 KiB) Viewed 2872 times
Last edited by geoberni on Tue Aug 17, 2021 9:41 am, edited 1 time in total.
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JOWETTJAVELIN
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Re: Fitting hazard warning lights - correct wires?

Post by JOWETTJAVELIN »

Do not cut any wires! There’s nothing worse than chopped up wiring. You should disconnect the wire at its terminal and take a feed that way.
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Re: Fitting hazard warning lights - correct wires?

Post by Oldmogman »

Hi Geoberni – thanks for your continuing help with this, it’s much appreciated.

Yes, I think you are right about the bright green wire feeding the tell-tale light on the indicator – the fact that it is thinner than the others would certainly suggest it’s dealing with less power.

I popped out the speedo to get a better look at the wiring, but was baffled by the plethora of thicker, dark-green wires that confronted me. I could see that one goes to the voltage adjuster box for the fuel gauge, while others go to the bulbs lighting the speedo, etc, but it wasn’t evident which of these might be switched (ie operating only when the ignition was on).

I could also see some hefty brown, white/red and white wires going to the ignition switch, but no green!

I’ve looked at the wiring diagram but I’m afraid I’m struggling identify which might be the switched live feed.

Are there any clues that might help a non-electrician identify the live feed wire visually?!
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geoberni
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Re: Fitting hazard warning lights - correct wires?

Post by geoberni »

Switched Live are dark Green and all come from the fuse as per this diagram:
Wiring1.JPG
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wiring2.JPG
wiring2.JPG (120.57 KiB) Viewed 2831 times
You need a permanent live to power the Hazard Unit.

Permanent Live are Purple after the fuse, but since you (hopefully) have a fuse on the feed wire, then it can be picked up from another place, such as the Brown/Blue going to the Ign Sw or Lighting Sw.

Now I believe all Minors with Indicators have the flasher under the bonnet, mine is on the wing next to the DB10 relay, yours is presumably on the bulkhead somewhere.
You may have to extend the wiring on the Hazard switch, but I would have thought they'd provide it with enough.
It might be appropriate to drill a new hole through the bulkhead if there isn't one suitable to feed through. If you do, then please put a grommet around the cables to stop them chafing.


Looking back to your original post, you said:
I see there is a spare connection on the fusebox that provides permanent power, which I assume this is the ‘unswitched point’ referred
But there shouldn't be a spare connection that is un-switched.
See this old post for a good description of the fuse layout: viewtopic.php?t=39914#p391951

Have we got to the stage where you can carry this job out?
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Oldmogman
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Re: Fitting hazard warning lights - correct wires?

Post by Oldmogman »

Thanks Geoberni

However, I’m afraid I can’t make sense of wiring diagrams, so I can’t understand which is the wire than runs from the ignition switch to the live terminal of the flasher unit, as cited by the instructions!

(I’ve carried out all kinds of of mechanical work on my Morris but I’m afraid I’m not an auto electrician, so I can’t relate what’s shown in the schematic to what I can see on the car!)

The later Minors have a different fusebox with several spare terminals which, as you’ll see from the pic, has numerous green wires running to it.

Could this be where I need to connect to?
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fusebox-low res.JPG
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geoberni
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Re: Fitting hazard warning lights - correct wires?

Post by geoberni »

Ahhh
I didn't realise that latter fuse box was introduced by then.

I'm afraid you have a slightly inappropriate obsession with GREEN..... Yes, there is a GREEN that goes to the Flasher which it the one your instructions are saying to cut.
BUT do not be confusing the power supply for the Hazard Unit (Purple) with the connection of the Green/Purple into the Green cable for the Flasher Unit.
That is simply a feature to stop the Indicators working if the Hazards are on. It's a Luxury that was not a feature of all after market Hazard Units. The one I fitted, an original mid 1970s unit, doesn't have it.

Do the following:
1 - In turn, remove one of the Green Wires from the Fuse Box, switch the Ign on and see if the indicators work, then replace it if they do.
By process of elimination, this will identify the Green that feeds the Indicators, because at some point, the Indicators will not work with the Green disconnected.
2 - Connect the 2 Green/Purple, 1 of them to the now vacated terminal on the fuse box, the other to the Green cable you removed/identified.
3 - Connect the Purple (permanent supply) on the Hazard Unit to the other fuse output if there is a spare tag. You might need to get one of these crimps if there is no spare tag.
https://www.ebay.co.uk/itm/122643259250 ... Sw7RRffhLg
4 - Connect the remaining 2 wires to the relative LH and RH indicator lines wherever you can. I have no idea where you will pick those up, since I don't have your installation.
5 - Connect the Black Earth cable somewhere convenient.

and somewhere along the way.....

6 - Remember to actually fit the Hazard Switch Unit somewhere you can reach....

That should hopefully sort you out.


Morning update, it was getting late last night... edit to add:
As an alternative to Step 1 & 2 above, if the 2 Green/Purple on the new switch will reach to wherever your Flasher Unit is, then simply disconnect the Dark Green on the Flasher and connect the Green/Purple wires to the Green Wire and the vacated Terminal.
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PhilAllen
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Re: Fitting hazard warning lights - correct wires?

Post by PhilAllen »

Hi,
I'd have replied earlier but my PC has been away for hard disk replacement ands only came back yesterday.
I fitted an ESM supplied kit to my 1969 car which I think has the same wiring as yours (assuming yours is standard like mine is).
These are the instructions that came with mine:
IMG_20210818_100531392.jpg
IMG_20210818_100531392.jpg (432.75 KiB) Viewed 2771 times
This is a photo showing the connections at the fuse box and flasher unit:
IMG_20210818_095706289.jpg
IMG_20210818_095706289.jpg (612.57 KiB) Viewed 2771 times
The purple wire that goes on the right of the fusebox is from the hazard switch and is connected to a spare terminal on the permanent live side of the fusebox. This achieves step 1 in the instructions.
The green wire which crosses the red wire from the inline fuse was originally connected to the switched side of the fusebox and is the supply to the flasher unit. This is step 2 in the instructions, Bernie has suggested above how to identify which of the green wires you need.
The 2 wires in a different shade of green are actually the green/purple ones from the hazard switch (I didn't realise till after I'd taken the photo that the purple trace is at the back on both!). One is connected at the fusebox in place of the original green and the other I soldered a spade to so that the original green could be connected to it. It doesn't matter which way round the green/purples go, they only stop the indicators being used when the hazard lights are on using a basic switch. This is step 3 in the instructions.
Step 4 I did inside the car under the glove box liner in front of the steering wheel (neither steering wheel or liner were fitted at the time which made life easier!). There you'll find bullet connectors for the green/white and green/red freed to each side. I can't remember if mine had 2 way or 4 way bullet connectors as standard - if they are 4 way there is a spare entry that I used, if it was 2 way I changed it to a 4 way one to get a spare entry. I think there is a 4 way earth wire bullet (black wires) with a spare way in there too.
I soldered spades and bullets I added to make sure I had good connections everywhere. The way I did it means it can be removed if ever I or a future owner wishes to do so without having messed the standard wiring up.
I mounted the hazard switch under the dash to the right of the steering column and found the supplied wires were long enough to go everywhere I needed to go.
It worked when I'd finished and still does, so I judge it successful, but I'm sure there are other valid ways of doing it too. I did have to clean up the inside of one of the bullet connectors (the earth I think) with a small file to ensure a good electrical connection.
I hope this helps you,
Phil
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Re: Fitting hazard warning lights - correct wires?

Post by Oldmogman »

Thanks Geoberni - that's brilliant!

I will follow the steps you suggest and let you know how I get on.
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Re: Fitting hazard warning lights - correct wires?

Post by Oldmogman »

And thank you, too, Phil - that's really helpful.

The ESM instructions are much better than the rudimentary ones that came with my unit!
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geoberni
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Re: Fitting hazard warning lights - correct wires?

Post by geoberni »

I've just found a copy of those instructions Phill came up with. On the Moss site...
https://www.moss-europe.co.uk/media/pdf ... ctions.pdf
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Re: Fitting hazard warning lights - correct wires?

Post by Oldmogman »

Thanks Geoberni - good stuff!

I shall be well armed when I go back into the garage at the weekend!
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