Suzuki a100/gofer, no lights

[goferfan]

Hello all, I'm a brand new member and trying to get some assistance with my problem.
I'm in the Toronto Canada area. Just picked up a 1980 Suzuki a100 gofer today. Starts and runs great, but has no lights at all, no headlight nor horn, nor turn signals or running lights. In Canada, the ignition switch only has two positions, off and on, as we are required to have full time lights, hence, no daytime or night/light detent on key ignition for such.
That being said, I pulled the battery cover and tested the 6 volt battery while motor was running and the meter showed 8.51 volts. So it appears that the charging coil is doing what it is supposed to do. I realize this bike has 3 coils and I haven't yet checked the one that's supposed to power up the lights. I believe reading through all the posts available on this model of bike, that the headlight is powered separately from the turn/running lights? I can't figure out if that is the case, why I don't have lights on either of the two circuits?

Any ideas? I'm also thinking of trying to locate the wires that supply voltage to the two circuits and wire direct to the battery. That should give me lights, but will it overload the charging coil? What if I install a second battery in parallel to accept more charging capacity? I suppose that may lead to even more draw unless I charge it overnights. Would that provide enough amps to drive a few hours each day without overloading the coil?

Thanks for any advice in advance.

[Teflon-Mike]

At a gues,your barking up the wrong tree... but then Knuk.... probably just barking..... anyway..

It sounds like a relatively primitive old bike electric set up... so you have a wiring diagram?

There will likely be 3 windings on the stator; one to provide unregulated bolts for sparks as a magneto. It wont be wired through the ignition switch, that will most likely effect 'off' by simply earthing the feed to the points (or greakers.. how Yankee are you?)

Second winding on the stator will make volts for the tail and head-lamp. These will take pretty much unregulated A/C volts from the winding.

Third winding will be the 'charge' supply; it will make the same sort of A/C volts as the lighting winding, but there will most likely be a simple zenner diode, to clip the supply volts at around 7.5-8v and allow DC to the battery to charge it, and supply the incidental; equipment like the horn and stop-lamp, maybe the side-light.

The suggestion you got 8.5v off the charge winding 'hints' that your zenner may be kerbuggered... but still.

On such AC 'direct' lighting systems, theres often a cross-over in the head-lamp switch so when the head-lamp is 'off' the bolts from that winding on the stator are directed through the zenner to assist the charging of the battery.

As it's effectively a separate stand-alone circuit, to supply sparks, the engine aught to run with no battery.

Electric for the lights would come directly from the magneto, so if engine running, you should get lamps. Only if the battery dead should you not get indies or horn..... b-u-t..... if the zenner fried, and the top-up cross-over in the head-lamp switch allows it, its possible that battery volts back-flows through the cross over to earth, and equipment no work.

Thst's where I would start prodding and poking. At the senner.

And as it's an old 6v magneto system, every damn bullet connector I could find. They corrode with age, and 6v isn't a lot of electric pressure to punch through the mold.
____________________
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[stinkwheel]

Check the fuse.

If you have nothing working but the spark, I'd have a look at the ignition switch, make sure it's connecting the battery to the reast of the bike. Even if the charging coil was knackered, you should still get flashers and brake light off a charged battery.

All the bulbs could have blown if it's gone a lot over voltage.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[goferfan]

thank you stink and teflon.
The fuse is good and there's power on the other side of it.
Battery is good.
Haven't gotten in to it yet, but since discovered that a 1980 has only two coils, one ignition other charging/power.
I'm thinking the rectifier is okay if charging sits at 8.5 at idle. I'll check later what happens when rpms are increased.
In any case, at the very least both the coils are functional.
That would leave the cross over as you stated perhaps causing trouble, or perhaps the key switch itself. I'll have to dig in to those two items first.

I know the bike would have been designed to be good the way it was, but it appears someone has been hacking wires in the harness where the battery sits.
I would think (please find any faults) that being there's only one coil that effects charging and lights, that I could simply attach direct wiring to the battery to supply the headlights and the rest of the powered items. ???

[goferfan]

Hmmm, might be mistaken on the number of coils. I read there was only two in "later" models, however I'm looking at the parts diagram for a 1981 tc100 and it does indeed have 3 coils.

I think first to do is remove cover plate and see exactly how many coils and test them for function.

[stinkwheel]

[stinkwheel]

[goferfan]

Stink,

I just checked voltages.
A/C at higher rpm is between 19 and 20
D/C at rest is 5.61
D/C at higher rpm is 9

I see that honda rectifier, it doesn't ship to Canada. I'll see if I can grab a number off it and try and find a shipper/seller that services Canada. What numbers/functions am I looking at to try and locate a replacement unit if I cannot get the Honda one?

I took a look at some of the hacked splices and there appears PO only dug into 3, so that's a relief. I will next take the ignition switch assembly off and see whats happening in there. Check to see if power is being transmitted by key switching on. I may be able to check for continuity back to the battery/harness area, that should help.

Where is the diode on this bike that you were mentioning? I see a little metal body with two wires in it, with a round fixture within. It's on the right side of the bike, on the frame just below the fuel tank. Is that it?

[stinkwheel]

You've got the idea, start at the battery and follow through towards the lights until you find where the electricity isn't getting through. The fact nothing's working is supicious. It'll go battery, fuse, ignition switch, light switch, bulb then back to earth and from there to battery negative then back through the ignition switch to earth.

My bet is the ignition switch is playing up. Note I'm working off a really sketchy wiring diagram I found online so if the wire colours I'm mentioning aren't what you have, my diagram may be old/wrong.

*looks at diagram* Hell, that's one weird ignition switch. The battery earth is switched through the ignition to turn the lights off... There are double the oppertunities for a failure here, each lighting circuit goes through that switch twice, never seen that.

Ok, meter tests on ignition switch:

With switch off. should be continuity between the black and one of the black/white wires. Open circuit between any other two.

With switch on "daytime". Continuity between the two black/white wires. Continuity between the green and the red/white wire. All other pairs open.

With the switch on "nighttime". Continuity between the two black/white wires. Continuity between all combinations of the yellow, red/white and grey wires. All other combinations open.

With the switch on "daytime" and everything connected, you should have battery voltage at the red/white and the green wires.

With the switch on "nighttime" and everythng connected, you should have battery voltage at the yellow, red/white and grey wires.

Check that earth from the switch. There should be continuity between both black/white wires and both the battery negative and the frame in either of the on positions.

As far as I can see (and I don't know your bike exactly, just familiar with how they did things then), the rectifier diode will be a roughly 1" x 1" thin black square with a hole in the middle and two spade terminals attached. Often bolted to the frame for heat-sinking.

Ignore the rectifier for now. This is not where the fault is, it's just a refinement. Fix the wiring fault(s) first. The lights should work with a charged battery. Until they do, there's no point efficiently charging your battery.

Any 6v regulator rectifier should work. It's just single phase but you could even use a 3-phase one and only use two of the wires. The one I linked to is a chinese copy of the ones fitted to Honda C50s in the late 70'/early 80's.

You'd need to do some fiddling around with the wiring to wire it in. I'd like someone else to check my thinking here, it's not entirely straightforwards...

Again, it's an odd setup and not the AC/DC one i originally thought you had with a 2-coil stator. The three coil system uses one coil for the ignition. One for charging at night time and one for charging during the daytime and all the lights are DC with battery assist. Presumably so you don't go over voltage when the lights are off because there is no regulation. You ought to be able to run both those charging coils into a reg/rec because they are 120 degrees apart so the voltage signals should overlap. The regulator should take care of the voltage. This should give you a reasonably healthy output.

From the diagram I see online, you'd want the green coming from the charging coil connected to one pin of the reg/rec and the yellow to the other then the charging output from the reg/rec connecting to both the green and yellow wires as they head up to the ignition switch. Reg/rec earth to frame because the ignition switch will isolate the battery anyway. Then remove the original rectifier and simply join the two wires together that go into it.

Weird...

https://www.oldjapanesebikes.com/mraxl_GT_Resource/manuals/a100_owner/img/page-1/a100_owner_0057a.jpeg
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Easy-X]

Kewl diagram And I thought my DT electrics were simple!

Over on the classic enduro forums they talk about the regulator with awe and mysticism. Whacking big zener diode as far as I can tell but anyhoo...

Re-reading the original post there's only off/on? If it were me I'd sit down with a nice cup of tea and map out what your particular ignition switch does, compared to that diagram. I would imagine it's just off/nighttime.

Charge the battery and disconnect the rectifier. Multimeter on red wire, follow it all the way along testing for voltage till you get to the orange wire, then follow that to all the places it goes: brake switch and clock from that diagram... worry about the charging circuit and headlamp later.
____________________
Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter

[stinkwheel]

[goferfan]

Thanks for the tips...I appreciate it.
I've got the wiring diagram for a 1978, that's as close as I can seem to find.
The battery is grounded to the frame.
Ignition switch does allow engine on/off, as does the kill switch. But, that's it for electrical function.
I'll do the wire chasing on my next days off....busy now for a week.

Thanks again.

[Easy-X]

Yes, while Mr. Stinkwheel's diagram looks pretty conventional - bar the earth switching - I suspect this variant is somewhat different. Time to get down to Poundland (thrift store?) and buy some coloured (colored?) felt tip pens

Break down the analysis into stages:

Battery circuit for the brake light, horn and indicators

AC circuit for backlights, headlamp, rear running lamp, charging.

Ignition: coil, spark plug, kill switch.

...get a bit messy if you try and draw all three on one piece of paper

Intersections between the above would be AC > Rectifier > Battery, and ignition switch interconnected with all Battery/AC/Ignition circuits.
____________________
Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter

[stinkwheel]

The one the wiring diagram above is for has DC lighting.

Usually small capacity Japanese bikes with direct lighting have twin coil stators with one for the ignition and a split lighting/charging coil. Three coil stator suggests it might be DC.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[goferfan]

Back...
So, dug in to it today, discovered a few things.
First, the PO only spliced what seems to me to be the bullet connectors, bypassing them with direct splicing, so that's a relief. I was expecting a rat nest of special wiring.
Did the troubleshoot of the ignition switch, it works as it should. The big alteration between the Haynes wiring diagram (I have the manual, British edition) and the wiring diagrams you folks provided me, is that the ignition here in Canada has only four wires. Black - constant earth, black white- key on earth, red-constant power, orange - key on power.
All that works.

No power to headlight, nor rear brake/tailight. Checked pigtail at headlight, nothing. Checked contacts under bulb at tail/brake light, nothing. Pulled wires from foot brake switch and nothing. I haven't got any farther on that as of yet.

Turn signal leads have power and left signal (testing with test light) powers up nicely (no flash). Right side powers up, but half the brightness, indicating to me it's either a grounding (earth) issue or faulty relay. Haven't moved any farther on that issue.

Horn. Horn has constant key on power as it should. Pressing switch does not make it work. Tried to open up the switch assembly (which houses the turn signal, high/low beam and horn switch) but the screw being lodged in tight, stripped out the head. I've cut a flat groove in it with file and sprayed some lubricant to sit overnight and I'll get at it tomorrow.

Horn is the only circuit I can see that actually uses a ground (earth). All the other circuits seem to use orange in series to undertake that function.

Oh, forgot to mention, I'm happy happy happy. I tested all three coils with the testing light and they all function properly. (didn't get voltage, just used tester). Did key on/off and engine running, all checked out so that narrows down any non-power issues.

[stinkwheel]

Well, if there is power to the horn and a flasher, it's mostly working.

Sounds like it's just chasing down broken wires/poor connections.

If you've got the proper wiring diagram for it, if you can post up a half decent picture, that would be really helpful in terms of assisting you with fault finding
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[goferfan]

Wiring diagram.
The one I have is for European/British models, got it online somewhere, it's the same one that's in the Haynes manual.

So, it's a little challenging chasing some wires that correlate with the diagrams, and some others that don't. As I mentioned, the N.A. model has only the 4 wires going to the ignition switch, the haynes/online diagram show 10.

I'm getting there though....I'm sure that it's just a corroded connection somewhere, or broken/pulled out of socket connection. It may be as well, that because the headlight bulb, tail/brake light bulbs are both no good, perhaps that's not allowing circuits to be completed and causing the issue?

I took the left hand switch assembly off and cleaned all the contacts. Horn now works like it should when pressing button. It was a bit corroded. Haven't yet chased the headlight and turn signals yet to see if I can get them to function properly.

[goferfan]

I've been able to power up horn, turn signals (without flashing, I haven't tried it with engine running to determine if that will enable flasher to engage).
Turn signal indicator light works as well.

I did have the neutral switch power up in the correct position, but it no longer does so. I must have dislodged something while poking and prodding.

I do not have power to headlights, nor to rear tail/brake light. Wiring looks intact, but given that the wiring diagram that Haynes (attached) provides is not what correlates to a N.A. model I'm having trouble of what to look for.
The orange wire (there's two, the one that is powered by key on works as it should) that powers up the brake light switch, headlights, neutral switch and indicator lights for both neutral and hi/low beam, seems to be the issue. I cannot decide if it is to have power continuously or whether it acts as a semi-default ground (earth) that closes the circuit.
As it is record cold here, I'll go out tomorrow and try again. I'm thinking I may wire a hot lead from the battery to the dead orange wire to see if that powers up the tail light/indicator lights, headlight.

For anyone reading, the key off has constant ground (earth) black wire, key on earth - blk/wh, constant power red, key on power orange. Notice the wiring diagram attached, from Haynes, has 10 wires in/out of ignition. N.A. bike only has the 4 mentioned.

[stinkwheel]

Just realised I may have got my knickers in a knot here regarding the head and tail light. I don't think what you have is what is on either of those diagrams.

In any case, according to both of the diagrams, the flashers, brake light, horn and neutral light should all power up with the ignition on and a charged battery and any orange wire should have battery voltage when the ignition is on.

Any black with white wire should be connected to earth.

The above is good, consistant through both diagrams we've seen and worth getting working before proceeding.

Here's where I got my knickers in a knot. On closer inspection I think it IS direct lighting, so the headlight will only work with the engine runing. The tail light may or may not (one diagram it does, the other one it doesn't).

Now we come to a bit of guesswork:

If you only have 4 ignition switch wires and a 2-position switch but a 3 coil stator it doesn't match either diagram. On both of the diagrams we've seen, charging output is switched through the ignition switch but you don't have a "lights off" position.

Can we assume the charging and lighting circuits are hardwired to seperate coils? Or is one of them redundant? Or are both going through your rectifier?

Only thing I can see is to test it to see what is connected to what.

There should be three wires coming from the stator. A green, a yellow and a black. Ignore black, it's the ignition coil output and is working as it should.

Headlamp dimmer switch. Do you have three wires? Should be a white, a yellow and one other (maybe grey?).

At a guess, that grey wire on the dimmer switch will connect to one or both of the stator coils so check for continuity between it and the yellow and green wires coming from the stator.

Then we have battery charging. The rectifier generally has two wires, a red and red on white. Is this what you have? The red should be connected directly to the battery. The red on white should be connected to one or both of the stator outputs.

Maybe worth checking the coils while you are in there?

With the green and yellow wires disconnected from the stator, measure resistance between the wire attached to the stator and earth (bare metal on the engine). I don't have an exact reading for your bike but it should be in the region of 0.2-2 ohms for each coil.

You could also measure AC voltage output with the engine running. Measuring AC voltage between the yellow then the green and earth. Again, not sure exact output but if it's over 6v, you're probably good.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[goferfan]

So I finally gave up on trying to locate the break in the wiring and connected the dead orange wire to the key on powered orange. That took care of everything. All lights work, all indicators work, brake/tail light works. It was very challenging trying to locate which wires do what, as the wiring diagram did not relay what a N.A. bike has. For instance, two separate orange circuits... which in my case the existing key on orange powered up horn, signals, and turn signal indicator. The other orange that travelled from back to front wound up powering everything else....oh, and the headlight only operates with engine running.

I've attached a couple of photos of what I was getting in to. I couldn't find the desire to go through that mess to locate a faulty orange wire and glad I took the easy way.

All 3 wires coming from the stator all appear to be doing what they should. Charging coil reads about 9 volts when engine running, the wire going to the zenner diode reads about 2 volts dc, but about 18 ac. on the other side of the diode, orange wire reads about 9 volts engine running, so I assume that's what is acceptable? The other one for coil works great. Bike fires up second or third kick when cold, first kick when warm. And so easy to kick over, very little effort required.

The PO had scrimped and saved on wire, (like really, how much did he actually save???) by splicing in new wires to just before headlamp. Not only that, but he did the same to all the wires inside the frame loom that you cannot see, just inside the battery compartment???? don't know what was up with that idea.

Only problem I have now is to locate a headlamp bulb and to get flasher working. Turn lights go on, do not flash. Can the flasher be repaired? I did a little research online, many posters state to update the light to a LED. I've found a few LED's online, any suggestions as to process or favoured setup?

Thanks for all the assistance, this is a great site.

[Easy-X]

Don't complicate things by switching over to LEDs just yet, seeing as the bulbs seem to work.

The flasher unit is quite cheap to replace and you should be able to use a generic 6V flasher unit. All you'd need to do is see if you have a 2-wire or 3-wire version.

2-wire - power in, flash out

3-wire - power in, flash out, clock indicator out
____________________
Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter

[stinkwheel]

At least they used a proper crimping die!

Get an electronic flasher relay. As above, buy by voltage and number of pins. The electronic ones flash at the same rate regardless of load so if you want to upgrade to LED, you don't need to piss about with resistors and such.

I think LED flashers bulbs are a great idea. You'll find ones that fit the standard bulb holders. Top tips: 1) Get amber ones, if you use white, they will overwhelm the tint on the lenses. 2) Get ones with multiple SMD type LEDs, not the dome type and you want them facing in all directions to get decent visability, not just mounted in one plane because LEDs are very directional. 3) Make sure they are going to fit inside the lens (I have some very expensive LED flasher bulbs that don't fit inside my indicator housing).

You can't use an LED headlight bulb with the AC lighting system, I've tried, they pop. You would probably be able to use an LED tail light but may find there is such poor earthing that both parts of it light up at once.

EDIT: I think the flasher bulbs are BA15s type. I use these guys but they are in the UK so you'd need to find a more local supplier. This type of bulb is ideal, I have them in Mrs stinkwheels YB100 which has a similar electrical system to your bike. https://www.classiccarleds.co.uk/products/2x-6-volt-warm-white-led-indicator-reverse-glb382-ba15s-21w-positive-earth-negative-earth
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[goferfan]

Stinky,

Any idea if a 12v led flasher will work? I can't find any 6 volt led flashers on this side of the earth. The only one i could locate is from the link you sent and delivery times range from weeks to months. There are some from Aliexpress, but they mostly state 6-12v, but then when you look at the specs, it states 12v.

Next bike will be 12v, without question....tough getting anything 6 volts rated on this side of the pond.

[stinkwheel]

[Easy-X]

Maybe all this should be in the Workshop section?
____________________
Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter