Starting Problems

[The Mighty Gryphon]

Checking continuity is matter of checking for low resistance.

Put your multimeter on the lowest ohms scale(usually 200 ohms) and touch each end of the wire with one of the probes, then look at the reading.  If there is good continuity the reading will be very low, near zero.  Generally, with the cheap multimeters I use, a good reading is going to be less than 10 ohms, depending on how much resistance there is between the probe and what it's touching.  It's a judgement call.  Having said that, a bad wire will usually read thousands of ohms, or will have a blinking display.

[Chaos]

I use the ohm function on the multimeter, and isolate at least one end of the wire.  Otherwise you may get a false reading through a ground or short other than the wire you're testing. I prefer the old fashioned analog meters over the digital, but that's because it's what I grew up with and I'm really old.

[Zfoster8]

I also use a cheap multimeter, i actually bought it specifically to work on this bike a few days ago. I'll check resistance as soon as i get home from work today, and probably order a new battery today for good measure.

@Laitch - i actually had to watch a youtube video just to see what terminals to plug the wires into, because i had never touched one of these before i bought one. The internet is an amazing tool though, thats for sure.

You guys (and/or gals) really kick ass, thanks for all the help.

[daveson]

No worries, this is better than a sudoku.

[stokester]

As others have said, using a multimeter in the ohms mode will indicate continuity from one end of a wire to another.  In your education on diagnosing electrical issues it is valuable to learn about tracing voltage drops.

While an ohm measurement works for many quick checks it will read continuity even if only one strand of a multi-strand wire is remaining.  If this is the case it will be unable to handle the load when energized.  A better check for many circuits is to do a voltage drop measurement.
An internet search will bring up a number of pages on the how and why.

[Zfoster8]

I just did the ohm check (hopefully correctly) by plugging the black terminal of the multimeter into the end of the wire that would connect to the starter relay, and the red terminal into the #11 socket of the plug that goes into the ignition module, and got a reading of 0.4.

[The Mighty Gryphon]

Looks like your wire is good.

[Zfoster8]

So that might mean that i need a new ignition module.

Pardon my ignorance, but if it worked by grounding the terminal going to the ignition module, could i just run a permanent ground wire there? I want to tell myself no, because that seems like a bad idea but I am curious.

It seems like a bad idea because the starter relay (edited) keeps fusing shut and I have to whack it every time i push the ignition button to get the engine and starter motor to shut off.

My basic understanding is that the ignition module is providing a temporary ground to close the circuit and once the ignition button is depressed it stops grounding that terminal, is that too far off?

[daveson]

I think you might be getting the ignition module and starter relay mixed up.  Don't hit the ignition module.  A workshop manual will be a big help if you havn't got one.

[Zfoster8]

you're right, my mistake. I have not been hitting the ignition module, that is much harder to get to to hit.

I do have a manual. Several actually. They are helpful, but not to the level that this website is.

[daveson]

The previous suggestions of Voltage drop or a loose connection are good.  Check if the connection is loose, and that it's fully pushed home,  the same as the other wires. And get some type of contact cleaner on them. It's good stuff.

The ICU allows earth through the brown/red wire to 85. Pressing the start button provides power through the black/yellow wire to 86 (and the fuel injection unit) This closes the contact in the starter relay from 30 (constant power from the battery) to 87 (power to the starter motor) so the starter motor turns.  When you let go of the start button,  power to the starter relay coil is lost, so the contact is broken, and the starter motor stops.

[Zfoster8]

I will work on trying to find some deoxit today. Doesn't look like any local stores carry it, I may have to resort to amazon. I will keep digging in and trying to fix connections and clean things up until it arrives and see if it makes a difference.

[Laitch]

I will work on trying to find some deoxit today. Doesn't look like any local stores carry it . . .

Call a music store that sells amplifiers.

[johnny]

https://stores.guitarcenter.com/eugene?source=4WWMWLGT&gclid=Cj0KCQiA-4nuBRCnARIsAHwyuPomvWsCiOe2y4hzBsX65OV1FDPK27JclighHNvi-qBZRc_Jh-E2UnMaAqxoEALw_wcB

https://www.guitarcenter.com/search?fromRecentHistory=false&Ntt=deoxit

i uses the d5... cause its moar than a contact cleaner... that and the flushing action... better than plunging action...


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j o

[The Mighty Gryphon]

You say the engine actually started and ran when you grounded the red/brown wire, is that correct???

That would tell me that the module is working as far as sending the spark signal to the coils.  The question now is why there is no ground connection for the starter relay.  I have been searching the internet for a circuit diagram of the module to see what may be affecting this ground but can't find any information about what is inside the module.

I suspect, but can't prove, that the module has some logic circuitry to turn off the starter relay once the engine is running even if the start button is held down.   Now that you know how to check continuity, you might want to see if there is a connection between pins #11 and #15 on the module.  I can't tell you where the pins are without the harness connector because they aren't marked on my module.  You'll need to get the locations off the connector.  It would be useful to know if and where there is continuity with pin #11.

I further suspect, but again, I can't prove, that wiring a hard ground from the starter relay won't hurt anything as long as you let go of the start button when the engine fires and starts running.  That might be your 'plan b' if cleaning the connector doesn't fix the problem.

[Laitch]

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[The Mighty Gryphon]

I just went out in the garage and checked starter operation on my 1994 K75RT. 

When the start button is pushed the starter spins and the load shed relay shuts off the headlight, the engine fires and runs.  I keep holding the start button down as the engine runs.  As the rpm's increase to idle speed, the headlight comes back on, indicating that the load shed relay is turning the lights back on.  That means the starter has been shut off even though I'm still pressing the start button.

This tells me that the ignition module is sensing that the engine is running and shutting off the starter relay and the starter because it's not needed. 

Going forward, I would try cleaning the connector and making sure it's tight.  If the starter still doesn't work, you have the choice of purchasing an ignition control unit, or just running the starter relay red/brown ground wire to a frame ground and remembering to let the start button go when the engine starts.  The sticky contacts you are experiencing in the starter relay may be the result of a weak battery or possibly a funky start button.  I would also get in there and clean the relay contacts well to remove any burnt metal where they meet.

[Zfoster8]

Gryphon,

I appreciate you checking into that for me. That confirms my understanding of the ignition module's workings.

I am picking up some deoxit after work and I will see if that makes a difference. if not, for now I will run the hard ground wire and clean up that relay and give 'er hell for a while until i pick up an ignition module. We are heading into winter here anyway, so realistically I am getting the bike running so that it can sit for four months so I have all kinds of time to get this resolved. I was digging around on some other posts on here and I think i will end up buying an Odyssey Extreme PC680 battery. I suppose shooting some deoxit into my ignition button wouldn't hurt anything either.

[The Mighty Gryphon]

Don't forget to keep us posted.

[Laitch]

Striking similarities in this thread and you seem to be heading toward a similar outcome.

[Zfoster8]

Laitch, you are right that does seem to be my exact same problem. I will dig into it more, i got to the bottom of the first page and they started talking about a Suzuki starter relay and I think I missed something but i am very curious to see how his problem was resolved.

To update everyone, I picked up some deoxit and blasted the connector and all the pins for the ignition module to no avail. No change. I ran a straight ground wire from the 85 terminal to the engine case ground above the shifter. picture attached.

I inspected the old starter relay and aside from the case being a bit busted up it is in fantastic shape so i swapped it in, and later on i will inspect the new bosch unit i had in there that was fusing shut.

I just rode the bike completely under it's own power for the first time!

Thanks everyone, and I will keep working on it because I would like to have the safety feature of the starter not running because i have been known to do something stupid like push the starter.


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[The Mighty Gryphon]

Glad to hear you have the problem corrected and your brick is running well.

I'm sure there are hundreds of posters here who will disagree, but personally, I think that start interlock in the ignition module is another case of Teutonic overthinking that leads to more problems than it cures. 

The sprag won't engage unless the engine is turning less than 300rpm, a situation that is virtually impossible.  While the engine is running the sprag ring is already spinning at half the rpm of the crank shaft.  Pushing the start button just reduces the speed difference between the inner and outer rings by 300 rpm.  Not really significant when the one of them is spinning at 3 grand. 

The only thing that might happen from riding around holding the start button is that you'll heat up the starter motor.  I wouldn't hesitate to use the external ground wire while I looked for a good deal on an ignition module.

[Laitch]

. . . aside from the case being a bit busted up it is in fantastic shape . . .

That is a description that begs for elaboration. Could describe how good shape would differ from fantastic shape? :-)

[Zfoster8]

The guts inside are in good shape. The case is ugly because it has been taken off before and someone was a bit forceful with it. Maybe "fantastic" was a bit of a gross overstatement...

Or maybe like a disney princess would say, it's what is inside that makes it beautiful.

Either way, i am just happy it works!

[daveson]

First,  I confess I sometimes suffer from wishful thinking,  but sometimes it hits paydirt.

What does that after market switch on your dash pad do.

Try the deoxit again.  Since the cover was off,  this deserves extra attention. Deoxit,  scrub it, clean it, deoxit it again.  Push it in and out the ICU a few times so the socket gets a spray as well as the pins. Then clean it,  then make sure it's dry before plugging it back in. Don't know if the brown wire was rested for continuity.

If the new wire was earthed at the ICU pin for the brown/red, instead of the gear box,  could that fix it? I realise I spose the Amps would be tiny,  so unlikely,  but still.

I'm wondering how the multimeter was used on the bike for the third test at pin 85 (with the result of 9.85V)

Hopefully not much fuel got past the rings,  into the oil,  while these tests were run with the fuel pump on.