Coverting tach/speedo incandescent bulbs to LEDs

Here's the latest in my adventures with converting my '74 Commando to all LED lighting. I want to do this for several reasons: brightness (especially for the tail light and brake light); the fact that LEDs draw so little current; and for longevity. The problem with them is that LEDs are pole specific, and Nortons are positive ground, so all the LED lights must be isolated. The latest project was the lighting in the speedo and tach. I undid the old wiring and removed the spring activated bulb holder. I then took a strip of three 5050 warm daylight LEDs, wired them up, cut the sides by about 1 mm per side to make the whole thing narrower (be careful: cut too much and you destroy the LEDs), then folded the LED strip around the centre LED (again, be very careful. Folding can destroy them, so test them after you've done the fold). Then insert the folded and wired LED segment into the original bulb holder, with the wires feeding out through the bottom, and silicone the unit in place around the top. Wire them up positive to positive. The photo shows an original bulb holder, and one modified to use an LED. The new version functions exactly like the incandescent, and pushes into the tach and speedo just the way the old one did.

I converted my commando to negative earth just to make it easier to fit led bulbs I changed the whole lot over I use a £5 honda reg/rectifier and a £3 led flasher unit for the indicators very pleased with the results cheers

I thought about converting the bike over to negative ground--because it does make a lot of sense to do so, but decided that keeping the LEDs insulated, and the bike positive ground, would be easy, while a wholesale conversion would be a lot tougher. So far, changing the lighting to LEDs has indeed proven easy, and it's an engaging project. The entire cost for the whole thing, including the new flasher unit, has been just over $10 US (about $1 million Canadian) and hours of fiddling.

FWIW some LED bulbs are available in non polarized versions (presumably they have a bridge rectifier inside) and I tried some on my own positive ground bike's instruments...but they only made for a minor improvement and the gauge lighting is still very uneven due to the bulb placement. Anyway, these are the ones I used and the result...

Did the same. That looks familiar. Not what I had hoped for.

Neilson, I like your idea. How does it look in the dark?
Jaydee

stay tuned..... picture coming.... tonight.....

OK, here are a couple of photos, both taken in my garage in the pitch dark. The first is of the instruments, now each lit by the LED lighting mentioned above. The fundamental problem is that the hole for the light bulb is offset and will therefore always over-light one side and under-light the other. Having said that, it is a helluva lot brighter and more legible than with the old incandescent bulb--and it draws essentially no current. ...I do have a question: why do my instruments have that blue and white upward sweeping arrow while the rest of you have the green dot?

This second photo is of the LED strip now running around the inside of the headlamp in place of the dinky running light that sits immediately below the headlight bulb--and as described in my previous post. Thus it looks like the Audi headlight of a few years ago--what Jeremy Clarkson described as "looking like a council flat at Christmas". I tried to photograph it head-on, but all I get in the photo is a blinding light. Hence the side-on shot. Again, it draws very little power compared to the original.

I would say those are not original Norton clocks. That's why you have those swooped lines, but I may be off base here, I'm only familiar with early bikes. But good job on installing the LEDs. Did you buy the cheap LEDs? 15' for $5 or so? I find the colors bad and inconsistent for the cheap ones. They usually look fluorescent or green.

DogT said:

I would say those are not original Norton clocks. That's why you have those swooped lines, but I may be off base here, I'm only familiar with early bikes. But good job on installing the LEDs. Did you buy the cheap LEDs? 15' for $5 or so? I find the colors bad and inconsistent for the cheap ones. They usually look fluorescent or green.

Click to expand...

They are original for the later bikes.

swooshdave said:

DogT said:

I would say those are not original Norton clocks. That's why you have those swooped lines, but I may be off base here, I'm only familiar with early bikes. But good job on installing the LEDs. Did you buy the cheap LEDs? 15' for $5 or so? I find the colors bad and inconsistent for the cheap ones. They usually look fluorescent or green.

Click to expand...

They are original for the later bikes.

Click to expand...

I think Dave is correct, these are the 1975 MKIII gauges. From old Britts 1975 Spedo, Tach, etc. Group 34 catalog page: https://www.oldbritts.com/1975_g34.html

The LEDs were from eBay and listed at $8.75 including shipping from China. You get 5 meters. I choose the 5050 LEDs with 300 lights on the five meters, and warm daylight. The company has quite a bit of info on the eBay site and I've been delighted with the quality. I gave a link on a previous post--can't find it at the moment.

I should also mention that in the photo of the running lights above, they are the only lighting in an otherwise pitch black garage.

As for the instruments, thanks for the info--I guess. My 'totally original' '74 has a '72 frame and '75 instruments. I wonder what other mismatches I'll find on my never-altered bike

Lucas provided a solution for cars which carry over to bikes, maybe the thought of forcing people to dismantle the dashboard to fix a bad earth made them go this way

2 wires, casing is fully insulated so you just swap the wires around until your led bulb works.





I have this set up working on a B44 and B25, both with speedo's and tacho's, +ve earth and LED bulbs.

rwalker28 said:

swooshdave said:

DogT said:

I would say those are not original Norton clocks. That's why you have those swooped lines, but I may be off base here, I'm only familiar with early bikes. But good job on installing the LEDs. Did you buy the cheap LEDs? 15' for $5 or so? I find the colors bad and inconsistent for the cheap ones. They usually look fluorescent or green.

Click to expand...

They are original for the later bikes.

Click to expand...

I think Dave is correct, these are the 1975 MKIII gauges. From old Britts 1975 Spedo, Tach, etc. Group 34 catalog page: https://www.oldbritts.com/1975_g34.html

Click to expand...

Yes the squiggly blue-and-white arrow is the NVT logo, "Norton and Triumph together :roll:

Kommando: so I spent all that time carefully isolating my LED strip in my instruments when Smiths had the solution...... As Homer Simpson said: "Dohhhhhhh........"

Don't feel too bad, I saw a listing for 7 of them and bought them all, still short one for next build and never seen any more in must be 5 years.

This is a possible alternative if way to hold it in can be found.

http://www.ebay.co.uk/itm/HIGH-QUALITY- ... XQDrJR1T1C

There is always the option to move on to the holders used on the Black Instrument holders used 73 onwards

Item: BULB HOLDER & LEAD ASSY INC.BULB (2 REQUIRED)
Part Number: 062086

These take a T5 bulb and have a plastic holder and if you turn the bulb through 180 degrees it reverses the polarity.

4 quid here, drop in

http://www.norbsa02.freeuk.com/goffyleds.htm

gortnipper said:

4 quid here, drop in

http://www.norbsa02.freeuk.com/goffyleds.htm

Click to expand...

Thanks for that. I'm interested in their comment that LEDs shine brighter through a lens of their own colour--now that I've done white LEDs in the red lens :cry: will have to do some experiments.

Yes, red led in red lens and so on.

Nielsen said:

gortnipper said:

4 quid here, drop in

http://www.norbsa02.freeuk.com/goffyleds.htm

Click to expand...

Thanks for that. I'm interested in their comment that LEDs shine brighter through a lens of their own colour--now that I've done white LEDs in the red lens :cry: will have to do some experiments.

Click to expand...

Essentially, a red LED through a red lens is passing red through red - so little light loss through a second filter. Another color LED through the same red lens would result in the red lens absorbing much of the other visible light, which the LED tries so hard to produce - and is tuned to do so, resulting in diminished output.