Speedo light toggle switch

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MorrisJohn
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Speedo light toggle switch

Post by MorrisJohn »

I’ve been looking at ESM and eBay for the toggle switch that switches the instrument light on/off and fits just under the speedo at the bottom of the dash. It’s missing on my car and I currently have no speedo illumination.

I can find generic and Lucas on/off switches, none of them specifically for this purpose. I don’t want to have to start drilling holes in the dash to get one of these switches to fit.

Can anyone tell me if the original can be bought anywhere?

Or…how one would wire the bulb so that when the headlamps are switched to dipped/main beam the instrument light comes on at the same time?
A bad day with my Volksie still beats a good day at work!

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simmitc
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Re: Speedo light toggle switch

Post by simmitc »

The speedo lamp wires are usually red with a white tracer. From the bulb holders (2) the wires go to the switch to which you refer. The supply to the switch comes just a short distance from the red wire that runs from the lights switch to the side lights. There is power to the slider switch only when the side lights are illuminated. If the slider is missing then the speedo lamps can be connected directly to the side lights - it is unlikely that you will want to drive without being able to read the speedo.

If you want originality, then ask Club Spares if he has a second hand one (contact details in Minor Matters).

I think that the design was originally so that the speedo lamps could be off when the side lights were left on for parking, but who bothers with parking lights these days; or perhaps it was for daylight use (like modern running lights) or even to save power when the dynamo was struggling to cope with the load?
MorrisJohn
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Re: Speedo light toggle switch

Post by MorrisJohn »

Thanks very much for the detailed reply. That’s very helpful.

I’ll probably just wire it to the side/dipped beam pull switch. I can’t foresee any occasion I’d want lights on and no instrument illumination.
A bad day with my Volksie still beats a good day at work!

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geoberni
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Re: Speedo light toggle switch

Post by geoberni »

MorrisJohn wrote: Thu Dec 09, 2021 2:35 pm
Can anyone tell me if the original can be bought anywhere?
It's a simple sliding panel switch, a quick internet search for Mini Slide Switch will reveal loads, including ebay.
You'll need to measure the spacing of the mounting holes and purchase the correct size accordingly, because manufacturers will differ.
I can't imagine modern switches are that much different from their predecessors 70 years ago.
Or…how one would wire the bulb so that when the headlamps are switched to dipped/main beam the instrument light comes on at the same time?
I'm not sure why you would want to?

As simmitc said, the concept was to save battery drain when parked up.
Unlike modern times, when people park where the hell they want to, Vehicle Lighting laws were far more strictly enforces. If you didn't park facing the correct direction, with parking lights, where required, you would soon get a beat officer knocking on your front door.
That's why the single filament 3w parking lamp was such a popular after market purchase.
A single 3w lamp drain on the battery instead of a probable 25 watts (from 4 side lights 5w each + number plate lights), plus instrument lights if your car didn't have this little switch to save a few watts.

Just an example....
Highway Code
Rule 248
You MUST NOT park on a road at night facing against the direction of the traffic flow unless in a recognised parking space.
Laws CUR reg 101 & RVLR reg 24
Rule 249
All vehicles MUST display parking lights when parked on a road or a lay-by on a road with a speed limit greater than 30 mph (48 km/h).
Law RVLR reg 24

Feel free to read the actual legislation on Road Vehicle Lighting Regulations 1989 reg 24: :o
https://www.legislation.gov.uk/uksi/198 ... ulation/24
Basil the 1955 series II

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jagnut66
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Re: Speedo light toggle switch

Post by jagnut66 »

Here you go:
https://www.ebay.co.uk/itm/384261253628 ... Sw33Jg5FLE
Could it be that someone has disconnected the original and not rewired the speedo illumination after?
Best wishes,
Mike.
1954 Series 2: 4 door: "Sally" -- Back on the ground with (slave) wheels and waiting to be resprayed......
1970 Triumph Herald 1200: "Hetty" -- Driven back from Llangollen in Wales (twice.....)
MorrisJohn
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Re: Speedo light toggle switch

Post by MorrisJohn »

geoberni wrote: Thu Dec 09, 2021 4:59 pm
Just an example....
Highway Code
Rule 248
You MUST NOT park on a road at night facing against the direction of the traffic flow unless in a recognised parking space.
Laws CUR reg 101 & RVLR reg 24
Rule 249
All vehicles MUST display parking lights when parked on a road or a lay-by on a road with a speed limit greater than 30 mph (48 km/h).
Law RVLR reg 24

Feel free to read the actual legislation on Road Vehicle Lighting Regulations 1989 reg 24: :o
https://www.legislation.gov.uk/uksi/198 ... ulation/24
Berni, thanks for this but as a former police officer I never stooped to the level of charging anyone with those offences :D

I do have a parking light on my car, but it’s not working (I suspect it needs wired).
jagnut66 wrote: Thu Dec 09, 2021 5:27 pm Here you go:
https://www.ebay.co.uk/itm/384261253628 ... Sw33Jg5FLE
Could it be that someone has disconnected the original and not rewired the speedo illumination after?
Best wishes,
Mike.
Thanks for this - switch ordered. Yes, that could well be the case. I’ve also ordered two E10 LED bulbs to “fit and forget” for the speedo.
A bad day with my Volksie still beats a good day at work!

https://www.glasgowmoggies.com
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geoberni
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Re: Speedo light toggle switch

Post by geoberni »

MorrisJohn wrote: Fri Dec 10, 2021 11:25 am

Berni, thanks for this but as a former police officer I never stooped to the level of charging anyone with those offences :D

I do have a parking light on my car, but it’s not working (I suspect it needs wired).

:lol: But you're from more recent times, back in the 40s/50s, when you would have been on foot patrol, relying on your whistle to summon the fellow officer from a couple of streets away (unless you were a Village Bobbie), you had to do something to pass the time at 2 am...... :wink: :)

You may find when you get the switch that although it works, it could be pretty grubby internally. f it's more than about 0.2 ohm, I'd give it a good soak in contact cleaner. :wink:
Basil the 1955 series II

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MorrisJohn
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Re: Speedo light toggle switch

Post by MorrisJohn »

geoberni wrote: Fri Dec 10, 2021 11:46 am
MorrisJohn wrote: Fri Dec 10, 2021 11:25 am
:lol: But you're from more recent times, back in the 40s/50s, when you would have been on foot patrol, relying on your whistle to summon the fellow officer from a couple of streets away (unless you were a Village Bobbie), you had to do something to pass the time at 2 am...... :wink: :)
:D I’m reliably informed stopping by pubs during the night to make sure all was well was a better way of passing the time.

Would soaking it in duck oil do the trick?

Changed days indeed.
A bad day with my Volksie still beats a good day at work!

https://www.glasgowmoggies.com
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geoberni
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Re: Speedo light toggle switch

Post by geoberni »

MorrisJohn wrote: Fri Dec 10, 2021 12:03 pm
Would soaking it in duck oil do the trick?
I'm not sure.
I don't use it myself and I think it's more of a Penetrating Oil and Damp Start, Insulator type product.
Whereas Contact Cleaners are designed to clean the electrical contacts of oil, dirt and general grime, some can even be used with power applied, others not so.
For example, a basic cheap one, Halford Own Brand is described as :
Removes tarnish, dirt, grease, dust, oil & other deposits
It prevents arcing between dry contacts
Ideal for cleaning ignition components & other precision parts
Sprays at any angle
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MorrisJohn
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Re: Speedo light toggle switch

Post by MorrisJohn »

Thanks. Will use the correct stuff then and give it a good clean up before use.
A bad day with my Volksie still beats a good day at work!

https://www.glasgowmoggies.com
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