How to convert to LED's and still have everything work

I recently converted my '82 SECA 750 to LED lighting throughout. I did this mainly to save power, since I've converted my bike to fuel injection, and the ECU, fuel pump, injectors, etc, draw a bit more current than I'd like.

Since I was trying to save power, I didn't want to add load resistors; that would have been counterproductive. Instead I needed to make some flasher and computer changes to accomodate the LED's while still maintaining stock SECA functionality.



Part 1 - the turn signals:

This probably applies to most XJ's. The main problem with swapping to LED turn signals is that they draw about 1/40th the current of the stock bulbs. This is a problem because the stock flasher relies on this current for its operation. The stock flasher (with self-canceller) works like this:

It uses a relay with an NC contact and two coils on the pole piece (one about 100Ohms, the other about .2 Ohms). There are also a 1200uF cap and 150 Ohm resistor, but these are actually just to ensure that the turn signals aren't on when the ignition is first turned on. There is no bimetallic element. The stock flasher has three terminals labelled B, C, and L.

Its operation goes like this:

1. The handlebar switch has a two pairs of contacts in each direction. One pair switches conductivity between the Br/W of the flasher and the selected turn signals and leaves it there, the other momentarily connects Y/R and B to the cancelling unit, enabling it.

2. Once enabled, the cancelling unit, which had been holding +12V on the C contact (Y/G) of the flasher relay, lets this contact float. This deengergizes the 100Ohm coil allowing the relay contacts to close.

3. Once closed, the relay contacts provide 12V through L (Br/W) to the turn signal pair selected by the handlebar switch. The current to them flows through the heavier coil and opens the relay. Once the relay is open, current flow stops, so the relay can now close again, and we have a flash cycle, based largely on the magnetic field build up and collapse time of the heavier coil of the relay.

4. Eventually one of two things happens:
a) the cancelling unit's counters expire and it puts 12V back onto the C contact, energizing the 100Ohm coil and locking the relay open (no more flashing), or
b) the handlebar switch is cancelled, which opens the contacts between the L contact (Br/W) and the turn signals (no more flashing)

Anyway, none of this will work with LED turn signals, so an electronic flasher must be substituted for the original one (which mounts under the frame under the tank). The problem is, nobody that I found makes an electronic flasher that will work with the XJ self-cancelling circuit. If you want your signals to still self-cancel, you'll need to make your own:

Actually, you start with a two-pin (or two-pin + ground) electronic flasher. I used a two-pin from Rumble Concept, but I don't like it much since its rate varies considerably with temperature. To adapt the electronic flasher to work with self-cancelling circuit, you need to add another SPDT relay.

Most accessory relays are SPST (that is, they have four pins - 2 coil connections, one common, and one normally open). For this application you need one that also has a normally closed contact (five pins). I used a Radio Shack PC relay, and its working fine, but you may want to get a Bosch-type one that should be a bit more rugged for vehicular use.

Wiring goes like this:
Stock flasher connector Br wire goes to the common pin on the SPDT relay.
The normally closed contact from the relay goes to the supply side of the electronic flasher.
The normally open contact on the relay remains unconnected.
One of the relay coil pins goes to ground.
The other relay coil pin gets connected to the stock flasher Y/G wire.
The load side of the electronic flasher goes to the stock flasher Br/W wire.

I super glued my relay to the electronic flasher, taped up the harness stub, and put a bit of RTV over the terminals before installing the whole thing.



Part 2 - the tail lights:

These are probably easy on most XJ's but are tricky on a SECA 750. I used local auto parts store red 1157 replacements (Jam Straits), though there are certainly better ones available online (SuperBrightLEDs.com for instance).

The reason these are tricky on a SECA 750 is that the SECA 750, and some others, has the on-board computer that checks a number of things including the tail lights. If you don't want the computer bugging you about your tail light being out, you need to modify it. I, being stubborn, not only didn't want it bugging me, but I still wanted the check to work, and I also wanted the check to work if someone put regular 1157's back in the tail light at some point in the future.

The guys that designed this computer were pretty clever. They included two circuits for testing the tail light. The first one checks the current draw of the running filiments in the tail light. The second one checks the current draw of the brake light filiments. Not only does it check the brake light filiments when the brake is used, it also pulses the brake light when the bike is first started (too quickly to see) to do an initial check of the filiments.

These checks of current draw are done in the computer itself. The wiring feeding the tail lamps runs through the computer. Inside there are a .47Ohm series resistor that allows measurement of the current drawn by the running filiments, and a .12Ohm resistor to check the brake lamp filiments. The resistors are the white ceramic blocks on the corner of the computer's circuit board:



An initial guess might be to replace these resistors with much larger values so that they would still drop the correct voltage despite the much lower current draw of the LEDs. The problem, for me, is that that solution would result in burned resistors if anyone ever put regular 1157's back in.

Instead, I replaced these two resistors with rectifiers. Semiconductors have a fairly consistent forward voltage drop that is largely independant of current. The whole process involved some trial and error and I got to disassemble and reassemble the cluster several times, but here's what eventually worked:

I replaced the .47Ohm resistor with a 1N5404 3A rectifier (Radio Shack P/N 276-1144). I had to Dremel down the leads a bit to make a good fit for the stock resistor holes. For the .12Ohm resistor, which needed higher current capacity, I used an NTE581 TO-220 cased rectifier. This is an 8A device. Both of these rectifiers drop enough voltage to indicate to the computer that the LED's are drawing current, but they also can carry enough current to work fine if regular bulbs are ever put back into the tail lamp.



In both cases, the cathode of the rectifier (banded end on the 3A rectifier) goes towards the edge of the circuit board.

Part 3 - instrument lights and the license plate light:

The best power savings by converting to LEDs are obtained for lights that are always on. Two of these are the backlights for the instrument cluster. They're only 7W, but, by converting those to LED you save a full amp of current all the time the ignition's on. That's 5% of the alternator's capacity... nothing to sneeze at.

Since I had to open up the instrument cluster anyway, to make the computer mods, I figured I'd do the lamp substitution at the same time. I also made a new bezel for the warning center, repainted my needles, and cleaned and polished everything while I had the cluster open.

Initially I tried finding some LED 194 replacement bulbs locally. Pep Boys turned out to be the only place that carried white ones. While their packaging claimed to be "brighter than OEM", I found them to be nowhere near as bright as the original 194's. So, instead, I ordered some bulbs from superbrightleds.com. Their prices, selection, and service were all excellent. Besides ordering the white backlight bulbs, I also got replacements for the amber (turn signal), blue (high beam), green (neutral), and red (warning) lights on the instrument cluster, and a white 67 replacement for the license plate light.

http://www.superbrightleds.com/specs/bulb_specs.htm

For the backlights I chose their warm white WLED-WW5 bulbs, and they worked great, very natural and perfect brighness, though they can be a bit tricky to install because of the LEDs sticking out the side. For the indicator lights I used their WLED-x4 bulbs, which actually turned out to be too bright. The green, especially, was blinding. I ended up putting blue masking tape over the green and blue LED's, and regular masking tape over the others. This reduced the glare a bit and also diffused the light so it looks more like the original lighting.



Summary:

So, I now have lights that are at least as bright as stock, will likely last as long as the bike itself, and draw considerably less power than stock. I would estimate that, at idle, and in gear, I am saving a good 48W (4A) of power. Put the bike in neutral, put your foot on the brake, engage the turn signals, etc, and the power savings goes up considerably; the brake lights alone save about another 3.5A over stock when engaged.

Cheers,
Paul

 

Great write up Paul with great pictures too. Thanks!

 

i don't think i am capable of doing this but wish i could.

 

Paul - great work! Now there's a great winter project I can maybe take on because the flasher parts pull right off and the work can be done in the warmth of my shop. Thanks for the inspiration!

 

It's really not that hard if you can solder. Paul did all the hard work figuring it all out...

 

Lo! Methinks we've seen the future of motorized wizardry come to pass.
All hail ...
Kudos - lovely job.

 

i must of been tired or something the first few times i read it.

 

Your whole project is worthy of being featured as a series of articles in one of the many Classic Bike Magazines.
I'm sure there would be ample interest in the Fuel Injection Mod's you've done. The LED conversion is great, too, but could be out of reach for some restorers without the skills to work on circuit boards.

I'm quite sure there are a good many who are doing LED Lighting,, that would like to have a Flasher Unit like the one you devised. That's one of those ideas that could make you a few bucks if you brought the device to market.

 

Paul, The manned mission to Mars needs you. You are the man!

 

i want to do the EFI mod!

tell me more about it...

 

Most of the background of the EFI conversion is covered here: http://residentialcolorado.com/SECA_750i.htm

Since I wrote that:

1. A guy ran my bike over when it was parked in a restaurant parking lot

2. Repairs from that neccessitated swapping to a MAC 4-1 exhaust (nothing else was available either new or at reasonable $$$$).

3. I installed a better duct between the airbox and throttle body, built a new fuel rail that fits better, and swapped in a second set of fuel injectors that I had had overhauled and flow tested.



4. I made a 36-1 wheel to replace the 8-1 wheel and removed the unneeded VR pickup.




I'm still doing some warm-up tuning and accelleration tuning. Sometime over the next few days I should get around to updating the doc with the latest developments.

Cheers,
Paul

 

went to the website...

its WAY over my head...

thanks anyway

 

Looking for a better solution I found this stuff



http://www.kisantech.com/index.php?cat_id=4

http://www.badlandsmotorcycleproducts.c ... BETCSM.htm

pricey

 

Pricey, yes, but also, neither of these auto-cancel systems takes distance into account, as does the stock Yamaha system. These ones are only time-based, so, when you're sitting at a long light, you'll need to keep re-enabling your turn signal.

 

Very nice SQLGuy.

So if I understand correctly you are augmenting the electronic flasher by adding a 12V SPDT Relay?

So aside from removing the old flasher and replacing it with this combo-deal, there are no other changes required for to maintain self-cancelling/flashing signal functionality?

 

Correct. That's it. This combo works the same way, as far as the canceller is concerned, as the original flasher, but, since it's using an electronic flasher, it doesn't have the load requirements of the original unit.

Cheers,
Paul

 

Thank-you for all your help SQLGuy. I put it together and will hopefully be able to test it out soon. But it may have to wait till Spring because although it has been warm in Toronto the last few days, the seasonal temp will return shortly and it's no fun riding in -15C+windchill.

I have pictures of the contraption in my gallery, in case you are curious to see how it looks. It's not the prettiest, and to be honest, my wife warned me about showing it to people for fear that they might think it's some type of remote detonator/etc... but y'all know the deal

I hope it works for me as it did for you.

 

I just finished up converting my tail/brake lights to LEDs and used your rectifier modification on the computer. Everything works great and I wanted to thank you for figuring this all out and taking the time to post it. I will tackle your turn signal/relay trick next, but I think I will pass on the fuel injection, it's tempting but I know my limits.
Cheers

 

Actually, you start with a two-pin (or two-pin + ground) electronic flasher. I used a two-pin from Rumble Concept, but I don't like it much since its rate varies considerably with temperature. To adapt the electronic flasher to work with self-cancelling circuit, you need to add another SPDT relay.


soooo.. i want to get my led blinkers to work with out self canceling. and i am probably dumping my stock gauge. What kind of replay do i need?

 

Just the regular motorcycle two-pin one from superbrightleds.com would work fine, or pretty much any other two-pin electronic flasher. Connect it to the brown and brown/white wires that go to the stock flasher; leave the green/yellow disconnected. You may need to try both orientations (i.e. switch the brown and brown/white wires around) because at least the superbrightleds.com flasher requires the load and supply to be on particular pins.

 

So the LED everything mod will eventually get worked into my current project...

The EFI will live in my dreams... I'm saving that entire page to my "porn" folder...

(porn folder = my folder of dream projects for cars and motorcycles)

 

Bringing up an old thread....

OK, so from my understanding, I want to buy the LF1-S-PIN flash relay.
http://www.superbrightleds.com/cgi-bin/ ... 1-PIN.html




Just to make sure I am reading this diagram correctly, the grey wire goes directly to the battery (via the wire for the existing relay), and the black wire goes to the turn signal switch on the handlebar (via existing wire). Am I correct?

I am not worried about the autpo-cancel at this point. I'll deal with that later.

 

For those that can aford it (sub 100 I think) many vendors now sell modules for proper led flashing and original autocancel or time based flashing, sometimes with brake flash options.

This won't help with Atari warning lights but oh well.

 

Do you have a picture of the before and after?

 

I'm in the process of rewiring my '80 XJ650, and I'm finding that the relays are mostly connected to plugs in the headlight. Is there a reason why they are originally located so far away? Would there be a problem (interference in the Diode, other relay, etc.) if I rewired the relays to be in the headlight with the rest of the wiring?

 

From the 1st post in this thread:

Has anyone actually done this? It is never mentioned in other posts. Usually just buy an electronic flasher till you find one that works...

I can live w/o the auto cancel but I'd like to try this added step.

I bought two 68 smd LED 1157 bulbs for my Windjammer fairing and I recently ordered K&S's DOT LED turn signals for the rear. So I'm hoping the flasher I ordered and the extra SPDT will work out...

P.S. I'll probably move the flasher and the extra relay to my "fake" headlight bucket hidden behind my fairing.

 

I think it's mainly a space consideration. There really isn't room for two or three more relays plus the self-canceler in the headlight bucket.

 

IS it possible to get those pictures back up?

 

I'd love to see the pics...I second the motion to get the pics back up!

 

The Company:

SignalDynamics.com

Offers a host of Modules to aid in LED Conversions, plus "Dummy-load" devices that you can use to maintain the Self Cancelling feature on the bike.

 

I already have dummy loads on the tail light circuit b ut I still get tail lamp out warning light. I bought the dummy loads from V-LEDS and I was instructed to put them across just the parking light circuit only. SQLGuy figured out that the XJ750 has two monitoring circuits, one on the parking light circuit and one on the braking circuit. The replacement LEDS I have in tail light sockets work fine.

 

I wish the pictures would come back, too.

 

because I am a visual person (as are a lot of people here), I had to draw this out. the quoted text is copied from the op.

"Wiring goes like this:
Stock flasher connector Br wire goes to the common pin on the SPDT relay. (pin 30)
The normally closed contact from the relay goes to the supply side of the electronic flasher. (pin 87a)
The normally open contact on the relay remains unconnected. (87b not pictured)
One of the relay coil pins goes to ground. (pin 86)
The other relay coil pin gets connected to the stock flasher Y/G wire. (pin 85)
The load side of the electronic flasher goes to the stock flasher Br/W wire."


LED signal wiring diagram close by bmonkey36, on Flickr

FU

 

now that I am finally getting around to doing this mod on my 83 maxim, I am learning a few things. one is that if you have a single signal indicator, you will have to install 2 diodes in the indicator wiring. my 550 seca has a right and left indicator and won't require the diodes. the other thing is that I can do this mod without cutting the main harness. the diodes will be installed in the cluster harness and can easily be replaced (or left in place) if I were to reverse the mod and go back to stock signal lights. I doubt that will ever happen. but you never know, I could end up selling it down the road to some purist that wants to put it back to stock, so there ya go. I will provide more details when I get the parts I just ordered from len next week.

FU

 

well I haven't received the parts I ordered yet, but I have made some progress. I picked up a couple diodes at radio shack (yes I am one of the lucky ones to still have a radio shack in my neighborhood). so the indicator light in the maxims grounds through the other side of the flasher system. goofy I know, but it works. therefore I have to connect one side of the indicator bulb to both signal wires through diodes and the other side of the bulb to a ground. turns out that the high beam indicator bulb grounds on the black wire in the indicator cluster harness. so the dark green wire ended up on the diodes and the chocolate wire got soldered to the black wire. the diodes are 200v 1 amp diodes. more than sufficient to run in either configuration.





liquid electrical tape is used where heat shrink tube cannot be slipped over the wire. I plugged it in for a quick test and it works perfectly.

FU

 

I never cease to be amazed at how quickly I get stuff I order from len. 2 days from Georgia to Seattle! and that's the cheapest shipping option. thanks again len! so I got the turn signal mod all wired up, without having to cut any of the main wire harness. I ordered some connectors from len to make it all possible. he has the male and female spade terminals I needed. I ended up breaking one of the female terminals trying to get it out of the terminal block, luckily I ordered extra connectors.

side note: the connectors len has are not identical to the ones the 83 750 maxim uses in the headlight and turn signal flasher connector. they will work, but you have to pry their retainer prong way out to make it happen. a small amount of uninsulated connector also sticks out the back of the connector shell.



luckily that was the only connector I broke. I barely had enough wire to repair it too.

I bought some male spade terminals to plug into the stock flasher connectors after I removed them from the connector shell.



then I insulated the connection with heat shrink tube. if I ever wanted to reverse this mod, I could just cut the heat shrink off and plug the connector back into the shell.



the spdt relay rests on the inner fender on the left and the brake light flasher can be seen on the right side. I think I might mount them to the inner fender with vhb tape, but they both are nestled in and aren't going anywhere, so maybe not. the ground for the relay is on a ground point that is also the lower left mounting bolt for the air box. you can see the one red wire on the left.



at this point, you are probably thinking, "omg! he used red wire for everything!", yup, I sure did. it's all I had sitting around and I know what goes where.

edit: I don't know why the last pic is rotated that way. it should be 90 degrees to that, and I don't know how to fix it.

anyway, that's it. easy peasy! I tried spinning the front wheel to activate the auto cancel, but I could not spin it fast enough to even register on the speedometer.

FU

 

Where do you get the spdt relay?

 

Radio Shack (if you town still has one). http://www.parts-express.com (or any other online parts retailer (Amazon too)) if you don't.

 

Cool. Thanks!

 

on my maxim 550 I used an led for the signal indicator from superbright it was bidirectional
if you use a bi directonal led bulb you do not have to add diodes.
this should work for most single indicator dashes

Part Number: WLED-W-120 cool white 120 degree $0.99
7500 K 5 lm 1600 mcd 12 mA .2 watts

bright enough for day or night
not bright enough for daytime use of highbeam indicator
they are on discount so I think they are being phased out

 

So I understand that to get the auto cancel functionality, you need an spdt relay as well as a two prong.

I'm going to do without, because I just want to get my signals flashing so I can take my full license test and ride without a supervisor... Legally.

So I got an led flasher from grote, for a pricey $26, and plugged it in, hoping for the best. Nothing. Obviously i was optimistic, but I was going with the trial and error method because internet is down at my house. Today it's raining, so let's do this!

There are some simple, cheap five-prong relays at Canadian tire, but I wouldn't know where to plug which wire, so I'm going to give up on the auto cancel for now.
The two prong relay I bought gas a load and an input prong, as well as a ground, as you can see in the picture. I'm guessing the Br/W and the Br wires are the ones I want to connect to, skipping out the connection to the cancelling unit. I simply don't know which, the brown or other, gets the load prong. I'll be switching them today to try then out, otherwise I'll have to find a set of bulbs, and I want to take my test soon so I can ride. Figuring out the LEDs I already have is the quickest option at this point. They've already been wired and soldered in, and I did a pretty good job of if, if I may say so.

Please help, gents. Thank you, ride well.

 

Br wire goes to input (it is the wire to fuse)
the Br/w wire goes to load

hook up the ground and your good


http://www.grote.com/wp-content/uploads/2015/03/01-4489-12_D_Web-Image.pdf

 

Thank you, you wizard.

Okay, granted, all that kept me from finding this was lack of a wifi connection, but now i am at a cafe.

That diagram, from what I can tell, is simply a breakdown of the internals of the flasher. I'll keep y'all posted.

 

I know this is an old thread, but it's so comprehensive and useful.

I want to do the same thing to my Turbo, replacing all the dash lights, extra gauges, tail lights, license plate light and turn signals to LED to reduce the current on the system and add in a phone charger.
Does anyone know if the tail light testing circuit in the computer works the same as the 750 seca? What lumen bulb is sufficient for the turn signals/tail light/dash? (I'm thinking 200-300 lumens for the tail light and turn signals, 30 for the dash. I'm going with the superbrightleds.com and there are a lot of options.

Does anyone have access to the images?

 

I suspect that it is different and similar to the 82 Maxim where it employs reed switches for the headlight, brake light, and tail light instead of the current sense resistors used on the Seca tail and brake circuit. And, as a side note, the limited testing that I did on the Seca CMS using diodes will allow running with LED or incandescent bulbs, but it also defeats the monitoring system so when bulbs burn out or filaments open a fault will not be detected.

I was considering trying a few, and as you mentioned there are a lot of options. One option is to go with Len as he has tested bulbs for the indicators and turn signals, but I don't think he offers the tail / brake light bulb. I wouldn't want to add tape as SQLGuy mentioned in page one of the post to the indicator bulbs, but I suspect it was the easiest option at the time. I believe he chose color matched bulbs to the lenses, which is usually recommended, but the consequences can be that it is way too bright.

The standard tail / brake 1157 bulb is 38 / 402 lumens, respectively. Did you choose these numbers based on research? Were you planning on using 1157R (red) bulbs to match the lens color for the tail / brake? Same would apply to the 1156 turn signals (402 lumens) and are bulbs being chosen to match lens color?

 

Your suspicions are correct, the Turbo Seca does employ reed switches for both the headlight and brake/tail light circuit. I saw some talk of magnets, and the reed switches are just on the edge of the gauges so I'm going to experiment with neodymium magnets to see if I can trip it, before deciding to jump it.

I picked cool white 30 lumen 5 led bulbs for the dash lighting and both 5 and 23 lumen for the indicators. I'll report what works for me.

I did some research on the turn and tail bulbs and found the same numbers. I was planning on using color matched bulbs but the white ones were rated at 80/290 for the tail, and 325 for the turn signals. I'm also thinking of adding another light to the top box as my luggage rack covers the tail light somewhat.

 

Preliminary tests look promising. I scraped a bit of epoxy off of the leads of the reed switch (high,low,brake) and was able to trip it from about 10-11mm away on the axis with one small neodymium ring magnet.

This looks adequate to basically glue one magnet outside the gauge cluster. Not sure it I can get the distance just right to receive a bulb out if the LED fails, but I figure it'll be good enough if it works. Now just waiting for the LEDs!

 

That sounds a bit magical to get the magnet placed just right so that the flux from the added magnet combined with the reed current magnetic flux would be workable. I suspect you would just have to disable the circuits with a permanently closed relay. And, if it could be done the tail circuit would work as it is in a always on state with USA bikes. However, the brake circuit would have to be modified to negate the filament check or the "TAIL" warning would be set whenever the brake lights are not illuminated.

It that one magnet per reed, or is the one magnet disabling all 4 reed switches?

I suspect there are other options that could keep the CMS bulb current function BIT, but they would either require some modification to the CCA or the willingness to use some load resistors. Since the brake trip point is 1 amp, and the tail is .5 amp, much smaller load resistors can be used when there is no need to match the wattage of the original bulbs.

 

One magnet per reed. A magical distance indeed, and I'm sure the process of gluing it and vibration etc would not make it possible. Maybe offsetting it slightly might get give me more leeway positioning the magnet just outside the reed's pull in lobe. I suspect alignment will be key too, one way will add and the other will subtract the induced magnetic field from the coil

Does the computer specifically check if the brake light is illuminated but the brake switch isn't activated? I'd have to look more closely at the wiring diagram to see if the switch is a separate input. I really don't want to add resistors, unless in the form of more brake lights

I didn't know the trip points were 1 and .5 amps. Thanks for that info!