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My tach 'works' as well as the alleged "test" in the service manual goes. In fact, my tach acts like a crazy spooked cat on LSD chasing imaginary flies. When the bike is off, the tach is at zero. When the bike idles, the tach sort of tries to make up its mind between 1k and 2k rpm about 5 times per second... ( just keeps bouncing between the two ). On the road, occasionally, somewhere past 35 mph, it decides to suddenly jump up to 7k then bobbles between 7k and red line ( same sort of bobbling it does at idle ). My tach couldn't care less how fast the engine is turning, but, i am convinced it at least "works".

Which leads me to my questions... The service manual states right up front that the tach "test" presumes the entire electrical system is working. Okay... so... the question is... what does the "other end" of the tach wiring hook up to? Is it a sensor someplace? Is it the ignitor? The R/R? both? Is it hooked to the wire that drags the crushed beer can behind the exhaust pipes with the antennae on top? That would certainly explain the way it acts.

:nerd:
 

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the take gets a signal from the black wire on the front coil.. the connector could be loose causing your symptoms
Thank you! I've taken the entire assembly apart. Cleaned it, etc. I decided not to replace the bee inside the tach, or the spider inside the speedo. Other than that though, i went as far as pulling the bulbs in the entire assembly and washing the plastic parts in the sink. Cleaned all of the connectors in the harness, etc.

So, the black wire on the front coil will be tomorrow morning's task at first light. Thank you again!

P.S. When i am comfortable enough with pulling off the fuel tank, i intend on building a brand new harness from scratch; actually two, one for each side instead of the huge single trunk. I'll be using the modern kind of automotive conduit instead of electricians tape as well.

:nerd:
 

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Discussion Starter #4
the take gets a signal from the black wire on the front coil.. the connector could be loose causing your symptoms
Coil has a red wire and a black wire, but the black wire goes back up into the harness. So i guess i need to cut the harness up and trace it back up the neck.

:frown2:
 

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Sparky!!!
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yup just looked at my diagram.. deifnantly the black wire to the tac from the coil.. both wires come from the cdi.. but the red goes to the other coil as well.

P.S. When i am comfortable enough with pulling off the fuel tank, i intend on building a brand new harness from scratch; actually two, one for each side instead of the huge single trunk. I'll be using the modern kind of automotive conduit instead of electricians tape as well.
been there done that. scrapped about 50 miles of spaghetti lost 90% of the redundant electrical BS. is it worth the time and effort.. depends on whats going on in the rats nest.
 

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Discussion Starter #6
been there done that. scrapped about 50 miles of spaghetti lost 90% of the redundant electrical BS. is it worth the time and effort.. depends on whats going on in the rats nest.
I am also thinking about pulling out all of the bulbs and replacing them with LED's with a resistor on the back. Need to do some homework on that first though to see if it's worth the effort in regards to saving current drain on the battery. LED technology has improved 1000 fold over the past 30 years. So if i can find a good LED that has at least the same candle power as the stock bulbs, uses less current to drive one, . . .
 

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I am also thinking about pulling out all of the bulbs and replacing them with LED's with a resistor on the back. Need to do some homework on that first though to see if it's worth the effort in regards to saving current drain on the battery. LED technology has improved 1000 fold over the past 30 years. So if i can find a good LED that has at least the same candle power as the stock bulbs, uses less current to drive one, . . .
LEDs are worth the effort, but if you use a resistor it cancels out the power savings. Just swap the flasher to the one compatible with LED. I have the number somewhere, been posted here too, have one on my bike.

The cheapest LEDs aren't so bright, best to pay a bit more. Have a couple of $3 bulbs in my tail light, now I need the good ones. The el cheapo license plate bulb is plenty bright though.

Before I would yank the harness, I'd test both ends of the wire in question.
 

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Sparky!!!
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I am also thinking about pulling out all of the bulbs and replacing them with LED's with a resistor on the back. Need to do some homework on that first though to see if it's worth the effort in regards to saving current drain on the battery. LED technology has improved 1000 fold over the past 30 years. So if i can find a good LED that has at least the same candle power as the stock bulbs, uses less current to drive one, . . .
again its been done before.. although i didn't use resistors. i was lightening the load to add it back elsewhere.
 

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Sparky!!!
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LEDs are worth the effort, but if you use a resistor it cancels out the power savings. Just swap the flasher to the one compatible with LED. I have the number somewhere, been posted here too, have one on my bike.

The cheapest LEDs aren't so bright, best to pay a bit more. Have a couple of $3 bulbs in my tail light, now I need the good ones. The el cheapo license plate bulb is plenty bright though.

Before I would yank the harness, I'd test both ends of the wire in question.
all 4 ends of wire in question... both sides of the 9 pin connector under the neck cover, the plug on the coil, and then the plug on the tac.
 

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Discussion Starter #10
yup just looked at my diagram.. deifnantly the black wire to the tac from the coil.. both wires come from the cdi.. but the red goes to the other coil as well.
.
Okay, so, i disconnected the 6P and took the black wire off the coil. The connection is fine ( wire is intact in the harness ). That leaves the black node to ground which is the "arrow" end in the diagram. That gave me a reading of 40 ohms to ground.

The bike fires just fine. the 6p connector is clean, but i'll need to rig up a mount of some kind to test the tach circuit any further since i only have two hands and work in a parking lot.

What kind of reading should that 40 ohms be? It's the primary side of the coil, correct?
 

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again its been done before.. although i didn't use resistors. i was lightening the load to add it back elsewhere.
A lamp is essentially a short circuit. LED's with a resistor in series would reduce the current drain and lengthen the life of the LED. It's the current being reduced that would make it worth the while. If the LED's are lighting up bright enough to match a bulb using less current, that saves the battery, more juice for everything else.

Each LED/resistor pair would only reduce the current drain on the overall system a "little bit", but multiply that by all of the various lamps and it might be worth the effort. Trick is to match the candle power of the lamp and no these would not be just any old cheap LED pulled out of the back of something else. The homework involved is finding the specs for the stock lamp, then doing a little math and shopping at an electronic distributor.
 

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Discussion Starter #12
LEDs are worth the effort, but if you use a resistor it cancels out the power savings.
erm... Ohm's Law. Increase R with constant V results in reduced I ( current ). The idea is to find a modern day LED that can put out the same candle power with lower current draw to do so. Then the matter becomes simple with a bit of math. 12v divided by the current required to get the job done equals the resistance in Ohms. Then to select the right resistor, square the voltage ( 144 ) divide by the Ohms, to get how many watts it will be dissipating. That would be the MINIMUM and a good rule of thumb is to double that power spec to make sure the resistor runs "cool". In the end, though, what's available is typically going to be 1/4 watt, 1/2 watt, etc... so just pick the next available size and that should do the trick.
 

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Discussion Starter #13
Just an update. . .

Among other various chores today, i bypassed the brown wire under the headlight completely and gave it its own connector. The tach is acting as hallucinogenic as ever. Tomorrow, among other chores, i will do the same for the other two black and black/yellow wires. Basically at this point, i am wondering how big of a square wave needs to hit the tach for it to work. That the needle moves gives me a hope/prayer that it's something else, but the only thing it could be would be the ignitor. Since the ignitor is working okay and the engine is running great, is there anything else it could be?

I'd hate to replace the tach ( if possible ) only to install it and watch it do the same crazy thing.

:nerd:
 

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Sparky!!!
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Among other various chores today, i bypassed the brown wire under the headlight completely and gave it its own connector. The tach is acting as hallucinogenic as ever. Tomorrow, among other chores, i will do the same for the other two black and black/yellow wires. Basically at this point, i am wondering how big of a square wave needs to hit the tach for it to work. That the needle moves gives me a hope/prayer that it's something else, but the only thing it could be would be the ignitor. Since the ignitor is working okay and the engine is running great, is there anything else it could be?

I'd hate to replace the tach ( if possible ) only to install it and watch it do the same crazy thing.

:nerd:
Black/yellow wire is Ground. The solid black wire is the only wire you need to worry about.. THE ONLY WIRE!!!!. The Tac directly represents the wave form coming out of the ignition coil.. You can test the output of the coil with a multi meter. The number displayed on the MM is then multiplied by 1000 to correspond to the tac. I still think your whole issue is at the connector on the Coil...

Like I have said, I have been through this electrical system front and back, upside and downside, and finally to the point where I decided that Kawasaki F-ed it all up and made my own. I am trying to think of one piece of stock electronics on my bike.. nope nada, not one piece of stock electrical left. Ignition Switch (Kabota), Handle Bar Switches (honda cb 750, gl500, and gl1100), Headlight (my own creation), Ignition Coils (Accell), Ignition Control (IGnitech along with IGnitech pickup coils), Fuse box (built my own, deleting all factory sensors and diodes), Dakota Digital Dash for instrument panel, and still working on custom lighting as I am not finding anything that looks right for my bike.

My point with all of this is.. I started out tracing down one wire, a squirly little black wire for the tac. and had I listened to "The Proffessor" and "Mater Mech", I would never have had to get so deep into the wiring. all I would have had to do is re crimp the connector for the Coil, and ran a dedicated ground from the coil mounting bracket to the frame. and boom I would have been done.
 

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But think of the fun you've had,Slim;)
 

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Discussion Starter #17
I still think your whole issue is at the connector on the Coil...

I would never have had to get so deep into the wiring. all I would have had to do is re crimp the connector for the Coil, and ran a dedicated ground from the coil mounting bracket to the frame. and boom I would have been done.
All three wires ( brown, black/yellow, and black ) were snipped from the plug today and given their very own brand new disconnect pairs. I even borrowed a real "crimping" tool ( thank gawd ) from a friend. The tach acts exactly the same.

Two things left... you mentioned a dedicated ground. The ignition coil bolts into the frame as a ground. I'll be removing that tomorrow just to clean it up.

The other thing. . . I am going to pull the tach apart tonight. I pulled it apart to the point of just having its case removed before, checked the connector inside it, etc. I suspect that if there is any soldered connections in the tach, they have dried.

One thing for certain, i can't f the tach up any worse than it is right now. :)

Regarding the multi-meter test. Do you mean to just check the AC voltage to ground as the bike is running? what are the general voltage levels one should expect?
 

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Discussion Starter #19
I meant Crimp the Black Wire to the coil.

use the MM for checking the Hertz
Ok the first picture is where i am at right now. That's the PC board inside the tach unit and i am just about ready to resolder all of the lands. I am also going to look up the IC and see if it's still in use/available... it's a T8016. Let you know later what my homework turns up.

Meanwhile, back at the farm, the second photo is my MM. It has Ohms, Volts AC, Volts DC, and Amps.

The black wire already goes to the coil, it was a dead short at the connector end. Do they T it off in the harness to go back to the ignitor?

I razor cut the tach harness and will run my own wires later when time comes to put the tach back together again. One of the bulbs was shot anyways and i think i'll replace them with LED while i am inside.

Regarding your opinion about Kawi F'ing up the electrical. All i can do is nod. This "connector" inside the tach has its own plastic seat but they had to kludge a bullet connector for the yellow wire ( temperature gauge ). Inside the wrapping harness for the tach, they split off the power for the bulbs instead of a single wire for both, same with the grounds, etc. To top off that spaghetti pile, they run the entire thing under that dash bracket begging for a pinch. I'll photo what i do to it, but it's still going to be a hope and prayer that it's the solder or the IC. There really isn't anything else it could be. The bike runs great. Did 60 miles up to the valley and back today. If it's the IC and it can't be replaced, i'll rebuild the tach with a digital unit inside. ;)
 

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Sparky!!!
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the Black Wire Ts off inside the harness IRC the splice is actually by where the fuel tank sending unit wires enter the main harness.

You can still get OEM Coils, or aftermarket makes OEM quality replacements. as for the ignitor box.. if it is determined to be bad (we will check into this tomorrow), I have a scource for aftermarket ones. Not cheap, but not too expensive.
 
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