Volts going to coils

[randy]

In reality, the TCI does not put out voltage to the coils. The coils are fed +12V through the resistor, dropping it to (now don't crucify me for this) 9V or 10V.

The TCI grounds the Gray / Orange from the coils to complete the circuit. As the pickups send their signals to the TCI, the TCI breaks the circuit to fire the coils.

[randy]

Dave, have a decaf.

So you checked the TCI and than checked the ignition module and you didn't know they were the same box?

Man, I'm confused, this electricimal stuff is difficult!

[DavesXS]

Originally posted by dbeardslee
Dave - The beginning of this thread didn't say anything about you testing the TCI. Sorry if it caused confusion, but assuming everyone has read all threads doesn't generally work. The reason I said check your TCI is because that's what feeds the orange and grey wires. That having been said, you might check your pickup coil gaps. Might be a little wider on one side than the other, which I suppose could cause the difference in voltage. Randy be the ignition guy, so maybe he could render an opinion on where to look.

I am guessing you didn't read the posts. Just responded to the title. Common mistake.
And I know it wasn't intentional, but randy with his like it or leave thing can go.


Too many variables. If you read the first post and see the initial problem was one wasn't firing, then it slowly climbed in volts and started firing. Now there the same. So kinda hard to diagnose now. But probly not the pickups.

[DavesXS]

Originally posted by randy
Dave, have a decaf.

So you checked the TCI and than checked the ignition module and you didn't know they were the same box?

Man, I'm confused, this electricimal stuff is difficult!

Yea felt pretty dumb there for a moment.
were all good now


Like I said above the problem is slowly correcting it self.
Hate when that happens.

[DavesXS]

Gonna do the soldier fix now. Or at least check if its done.

[DavesXS]

Pick up wires good. Look and feel brand new.

while running. I got 13 in. At idle the wires have 10. When I rev it up it drops to 7

Its my understanding the signal from the pick ups goto the module. Then the module fires the coil signals based on that. But its a 12 volt signal that gets fired. You want as much as possible because the coils have to step it up. The pickups wire is only supposed to put out 8 volts at idle and goes up when you rev. I saw this when I had a 4cyl tach running off the pickups signal. It does what its supposed to.
So it has to be the module not correctly giving out its signal to the coils.

[randy]

ok, last time.

The TCI DOES NOT 'put out' signals to the coils. The TCI grounds the coils to complete the circuit, then breaks the circuit to fire the coils.

If you have low voltage problems, it's most likely bad connections. If you have corrected all of the connections (clean AND tight) outside the TCI, then do the solder fix.

Good luck.

[oldyam80sg]

Not meaning to but in, but i thought i had a problem with the coils on my SG last year. I had bought a spare set of coils hoping it would solve the non firing problem. That didn't work.Finally got in touch with Randy one day when i drove to PA.The solder fix i tried didn't work so i brought it to the expert.Something must have gone bad in the TCI and the solder fix didn't work for Randy also.Randy sold me a used unit and have been problem free after that.I have since bought another spare off of Rider parts.com.If the TCI is the culprit,they are available you just have to look for them.Good Luck!I know that these things can be frustrating but you eventually will nail it!

[egsols]

I was reading in my Haynes and it also mentions checking to make sure that the TCI has a good ground before condemning it.

[DavesXS]

Originally posted by randy
ok, last time.

The TCI DOES NOT 'put out' signals to the coils. The TCI grounds the coils to complete the circuit, then breaks the circuit to fire the coils.

If you have low voltage problems, it's most likely bad connections. If you have corrected all of the connections (clean AND tight) outside the TCI, then do the solder fix.

Good luck.

OMG your splitting hairs now.
The breaking of the current allowing it to flow is in fact "putting out a signal"
"fire the coils" same as "fire a signal" Also the box can be called a trigger box

And the TCI seems to be the weak link on this bike.

For me its easier to replace it. Then if I continue to have a problem I know 99% sure its not the TCI and I will have a spare. But I been racing cars since 14 and I know how to ring wires and trace problems. Just want some in site to speed the process. (and it did) so thanks to all!


Thanks you guys for the help,
But I have to replace the tci now because thats where I am at in the process.
I have a MSD iggy box and coils to install but need to make sure the signals going into it are what there supposed to be.(12volt)

[TopCatGr58]

Re: Volts going to coils

Originally posted by DavesXS
The gray wire isn't putting out the same volts as the orange. It wasn't putting out enough to fire for a while(1-2volts)
It eventually made its way to 6-7 volts where it can fire. Then eventually went to 10 volts. The orange has 11 but when the gray had 6 the orange had 8. It maintained that kind of difference while climbing to what it is now.

Can some one who's bike fires great check the volts coming from the ignition control unit gray and orange wires on the end?

Any ideas? Think I need a new ICU?

Thanks
David

Hey Dave,

In your first post quoted above, you asked whether you needed a new ICU(ignition control unit), and the other member provided a link to Randy's Page where you could find diagnostic techniques to verify whether the ICU as you called it, which we all call it a TCI(transistorized controlled ignition). He assumed that you knew that they were the same, many new members use slightly different terminology for the same thing because they are familiar with that different term, but know that they are interchangeable.

No body here is getting paid for being here, we take time out of our LIFE to come here to offer assistance AS BEST WE CAN in this remote environment to help others get their machines back into running order. No one tries to make anybody look like a fool...well...Xcept for Prom, but that's a different story!

It's very difficult troubleshooting these things in person, much less from thousands of miles away over the NET, and it's easy to misinterpret meanings, phrases, words, tone of message etc! But after we have gone to the effort to try to help, and then we get our heads bit off, then we tend to feel that the person asking for help apparently doesn't appreciate out attempts, and so they CAN take it or leave it!

So...getting back to your situation, as has been posted in this thread, the TCI controls how the coils behave, but first, if it doesn't have a good ground, it can't properly ground the coil circuit to make them work properly. Secondly, IF the TCI's connections are bad, corroded, soldered joints bad, etc., same thing, so that's part of why "we" wanted to be sure that the TCI was eliminated as a possible culprit.

The electrical system isn't the easiest thing to understand either. As was attempted to explain, the grey and orange wires don't provide any power, they are just the other/grounding side of the ignition coils, and the readings for the power coming from them is as the power goes thru the red/white primary wire THRU the coil and out the (-) terminal to the grey/orange wire where it is then grounded thru the TCI to ground completing the circuit. IT's when the ground is interrupted is when the coil actually then fires due to the magnetic field collapsing.

The 80 xs11 still has the ballast resistor. During STARTUP/cranking, the power to the coils is BYPASSED around the resistor via the TCI and sends 12 volts directly to the ignition coils to provide a stronger spark to make starting easier/quicker. But once the engine is running, then the power is routed via the TCI THRU The ballast resistor which drops the running voltage to about 9 volts going thru the Red/White wire to the ignition coils.

The ignition coils Primary wires(red-white and Gray/Orange)also are supposed to have ~1.5 ohms of resistance, same as the ballast resistor, which would drop the voltage coming out of the coils going into the Orange/Grey wires down to about 6 volts.
You say you have 13 volts going into the coils when the engine is running???? OR are you just measuring the voltage at the battery and assuming the 13 volts at the red/white wire at the coil while running? We don't want to assume anything!

Okay, don't know if this helps or not, but remember, WE ARE NOT THERE with you so we can't actually see what you are doing or trying, just by what you tell us, and we can only suggest what we know or have experienced, so hope you can see where "WE" are coming from, and will be a little more understanding about any future tech/troubleshooting discussions?

[DavesXS]

Thanks TC thats something I can understand.

The 13volts I was measuring was the red/white wire going into the TCI. Assuming it was supply for the TCI. Really nothing to do with my problem I guess.

The way it was doing at the end is what your describing as normal. It sounds the same while running. First time I cranked it in 2 days one coil wasn't firing, and gray wire was 1-2 volts. But it just self corrected.But motor off and switches off I'm supposed to have 12 volts on the coil wires and still don't.
When I crank it drops then jumps up. This sounds like the resistor right? Not sending the volts on start like supposed to? Or maybe the coils? My solution at this point is start replacing everything I can. resistor, tci, any thing else I should eleminate? Pickups look brand new and if it was them or there wires it would have had a problem with both coils right?
I think I'm gonna stick the coils in and see if the volts on the coil wires change or improve.

[TopCatGr58]

Remember, the Ballast resistor is NOT in play during cranking, so you should be getting 12 volts at the red/white wire AT the coils. I wonder if the manual...is it a clymer's folks.....that says it should read 12 volts on the GREY/Orange wire...this doesn't make sense to me after thinking about now because we are measuring the voltage after it has gone thru the coil with 1.5ohms resistance, so I would think the voltage would be about 9 volts with the key on OR starting/cranking but not the full 12 volts??

Dave, if the voltage is dropping to only 1-2 volts on the gray/orange wire during cranking, then it still sounds like there is some corrosion on the connectors SOMEWHERE, depending on how much actual true voltage you have going into the coils.

Have you checked the ohms on the primary wires of the coils by totally disconnecting them from the harness and then testing across the red/white terminal and the Orange or Gray terminal??

Also, If you find you have 12 volts going into the coils AT the coils, but still have poor 1-2 volts coming out of ONE of them, you can try swapping the orange and gray connectors AT the coils, and swap the plug wires...IF you want to be able to test it while running so that the wires now on 1-4 go to 2-3 and vice versa. Then retest the voltages coming out on the gray/orange wires.

IF the low voltages stay with the same colored wire, gray or orange, then it would point to the TCI as not providing a proper ground to complete the circuit to allow ALL of the power to flow thru the ignition coil. But if the voltage drops on the Other colored wire, then the problem is following the igntion coil and sounds like the ignition coil is suspect! Good Luck!
T.C.

[81xsproject]

You might want to read the manual for the MC2. I think you might be able to ditch the resistors. I am pretty sure you can because the MSD is inline between the coils and the stock iggy. However, I am not sure because my '81 doesn't use resistors in the first place.

[DavesXS]

I'll check on that in the instructions.

Could the clymers be wrong?

Since you said the tci is down stream the coils I'm going to focus there. First checking volts into coils. I had it backwards. I thought I was checking volts into them. Betting on coils now. But thanks to 81xsProject I have a set of msd's. And the box is piece of cake to install. I had gotton the carbs,floats, idle all tuned up and want to make sure tci is good. That way when I do the install, if something doesn't run right I'll know what its not. Now thinking doing the install will most likely cure it. And if it persists then we know its the TCI.

THanks