The + earth Norton/ - earth LED riddle

GDay Chaps,

Has anyone managed to work out how to wire up negative earth indicator LEDs on a positive earth system?

I have the o/e Lucas indicators on my mk 3 850, which earth through the frame (no return wire). I'm thinking that to fit LEDs (which only seem to be available in negative earth for indicator bulbs), it's necesary to isolate the indicators and connect this live wire to earth somehow. I've trawled the forum and several folk say it should be possible, but I can't find any threads about anyone who's done it...

Any thoughts? I'd like to avoid having to go negative earth altogether- I've got my instrument, pilot and rear/brake lights going with LEDs now, but all these have a return wire that means you can just swap them over- or are available in positive earth to begin with. I've made a list of all the components that need a postive earth and they include (unless I'm mistaken) the 2MC capacitor and the starter solenoid... There may be others!

All thoughts welcome, someone must have sussed this riddle by now!
Many thanks,

crusadersports

GDay Hotbot,

Thanks for the link- I did look at bulb last forever but couldn't find a price. One went up on the 'for sale' site a few months back for $100US. I was hoping some ' lecky wizard had sussed how to do it by juggling a few wires... and giving up a few less real ale tokens....

Many thanks mate,

crusadersports

Its tricky do the way Norton switches its signals and why it too a whiz kid and black boxes to pull it off. Simplest is just isolate each LED module with enough of em in there to drop voltage to tolerance or put resistance in path.

I've 2 Cdo's one gets only Norton parts the other gets no Norton parts and used to run Bruces kit but now is - ground with solid state switches and light controls so no need or desire to re install. It has running light box adapter I never figured out to install. Otherwise has a cigarette pack size control box and tail light/tag light plus signals modules that fit Norton Lucas stems. I think might have a few extra modules Bruce sent at one point with market saturated and lasting so long. Was working when removed 6 yr ago. Make offer we both can live with.

The easiest way is to convert to negative ground. Only the battery, the assimilator ,the capacitor and the Zeners are polarity sensitive.
Just replace the zeners with a power box and reverse the leads to the battery and capacitor and replace the assimilator with a tri-colr led monitor and your home free. The starter solenoid doesn't care. If you have electronic ignition it will need to be re-configured. Jim

Thanks guys for the suggestions. (Hobot I've PM'd you separately),

I don't want to convert to negative earth- call it a mental block- changing a few bulbs and wires around is nothing that can't be undone to return the bike to original spec in half and hour.

What seems crackers to me is that it's a doddle to get a rear/brake light LED in positive earth, yet no one seems to make/sell a simple LED replacement for a single filament 21w bulb in positive earth. If there's enough demand to justify making LEDs in positive earth at all, then I don't see why that shouldn't include indicator ones? Hmmm....

crusadersports

Yep sir you now understand the complexity to create LED positive Earth for obsolete British beasts. I'm away from big computer with email so later today to access your pm. I don't think any rats got to the stored LED kit, which I would re install on Ms Peel special except she ain't going to use those stinking plastic chrome earth path, knock off prone Norton things no more. I stuck the LED brain box under seat area jammed in foam zip tied in place.

crusadersports said:

Thanks for the link- I did look at bulb last forever but couldn't find a price. One went up on the 'for sale' site a few months back for $100US. I was hoping some ' lecky wizard had sussed how to do it by juggling a few wires... and giving up a few less real ale tokens....

Click to expand...

Did you try contacting British Cycle Supply? They are the retailer for bulbs4ever...

Cheers,

- HJ

crusadersports said:

I don't want to convert to negative earth- call it a mental block- changing a few bulbs and wires around is nothing that can't be undone to return the bike to original spec in half and hour.

Click to expand...

I was thinking :shock: that if the indicator bulb holders were to be electrically isolated from their housings, and an additional wire (thin wall cable would do) fed through each stem and connected to the bulb holder then it may be possible to reverse the polarity at the bulb so negative earth (Goffy type) LED bulbs could be used?
The new wires would be the negative (connected to the left or right indicator circuits) and the original wires would become positive (earth). Alternatively a plastic bodied two wire bulb holder could be sourced to take the place of the original metal holders with the wires connected as required to operate the LED bulbs?

Thanks Chaps,

HJ, thanks mate, I have emailed BCS- you have to request their entire price list to me emailed to you... Hobot has a second hand one, if we can strike a deal . In the meantime....

LAB- excellent, many thanks, this is the sort of thing I am scratching my head about. Looking at the parts book, the bulb holder is metal,the indicator body is plastic and obviously the stem is metal. Now what I don't understand is how the original indicators earth through the stem when the plastic body is between them and the bulb holder.... :shock: Could you enlighten me??

I've not seen any repro Lucas Indicators (like Goffy, for eg) with a 2 wire bulb holder- I s'pose because they are replacements for the o/e Lucas. May be a 2 wire bulb holder could be purloined and fitted in the Lucas body, but the wire would have to be attached to the bulb holder somehow(?) and then isolated all the way back to what would be a live connection.

It's beginning to sound like I'd be better off fitting some more modern indicators that feature feed and return wires- eg: http://www.vehicle-wiring-products.eu/V ... duflbo.jpg

and then sussing if reversing the connections will allow negative earth LEDs to function. Oh what fun! May be in time Goffy will market such a conversion for positive earth bikes.

Thanks for all the input guys!

crusadersports

crusadersports said:

LAB- excellent, many thanks, this is the sort of thing I am scratching my head about. Looking at the parts book, the bulb holder is metal,the indicator body is plastic and obviously the stem is metal. Now what I don't understand is how the original indicators earth through the stem when the plastic body is between them and the bulb holder.... :shock: Could you enlighten me??

Click to expand...

The metalised "chrome" finish on the Lucas indicator housing is the actual electrical conductor between the bulb holder and stem! However, the chrome finish does not make a very good conductor once it begins to flake off and corrode-so owners often add another earth wire to improve dodgy flasher operation resulting from bad earth connections!

HI LAB,

Thanks for clarifiying the er, electrical integrity of Lucas Indicators...

We'll have to call that a thin veneer of engineering, me thinks :mrgreen: !

crusadersports

bulbsthatlast4ever are awesome!!!! I just got my custom turn signals today. They'll make up a professionally engineered circuit board for any light you send them!

crusadersports said:

HJ, thanks mate, I have emailed BCS- you have to request their entire price list to me emailed to you... Hobot has a second hand one, if we can strike a deal . In the meantime....

Click to expand...

Yeah I'm not really sure why they do that... gives the customer (me!) time to think before making an impulse buy!

OTH they really do provide great customer service once you order...

in my learning curves I wired two leads to the front signals not to reverse polarity but to have non intermittent signal function, by simply scratching off - the rest of the flaking decaying chrome veneer where bulb mount and screws touched.

LED kit has dual isolated leads no plastic chrome to worry with.

G'Day Chaps,

Thanks HJ & Hobot,

I really couldn't believe it when LAB explained how the Lucas Indicators earth- talk about cutting corners- I can see the logic, but not the wisdom! It's amazing to think a qualified electrical engineer thought that was a good idea. Says alot about how these things were regarded in the 70s- as some newfangled, unnecessary and grudginly fitted luxury item- like a speedo and pillion footrests were in the 40s!

Anyway, I would be very chuffed to hear from folk who have fitted the 'bulbs for ever' kit. Hobot has sent glowing (sorry!) reports :mrgreen: Anyone else tried these things?

Seriously, thanks to all who replied- 'bulbs for ever' sounds the only practical way of converting to LED while retaining the o/e Lucas Indicators- that is until someone markets LED indicator bulbs in + earth.

crusadersports

Bulbsthatlast4ever are almost as attention getting as Goldwing X-mass lights and tough as nails, so much so he'd had to expand market as no one buys a 2nd set nor any spares for Cdo installs. I'd be re-using mine but Ms Peel can't have anything sticking out to be knocked off anymore and Trixie didn't come with signals so keeping her faithful, but did add 2nd mirror for city multi lane sneak up traffic. Off in a few minutes to see if rats got through the protective plastic container instead of sealed tin can lessor tough components require.

I've got the tail light too. It's very bright! easy install

I also have a tail light from Bulbthatlasts4ever on my Commando and on my T14E as well and I love it; they are bright and very well made. I consider it a nice security feature. On my VFR I have a tail light modulator which is an excellent security improvement in the trafic crowded with zombies!

Crusader, Here's what I got to go.
Basic black box interface, exposed with pig tail.
Running light intterface box option in zip bag [never installed].
5 signal LED modules, [ 3 uninstalled new. as of ya could tell]
1 tail light LED module with modified rubber gasket bulb holder to ease install.
2 decent but aged/abused short stem signals/lenses.

Retails ~ $100 for signals, $70 tail light, $50 for run light adapter not counting the extra signal module. I did totally crash a front one to smithereens, hm maybe two as can't find any remains of front longer stems removed ~6 yr ago.

http://rides.webshots.com/photo/2569882 ... 1179URDAxs