Startus Interuptus, Help Me Understand It. Updated ?'s

[Tom H]

After reading many threads about it, I'm feeling confused. I feel like I'm trying to stop a device and can't figure out which wire to cut.

From what I understand, the main issue is to many amps through the key switch and starter button. This causes the key switch to go bad. Also I have read something about the wire from the relay to the starter solenoid being too small

If I understand the wires right, and I'm going to overly simplify this, the battery goes to the key switch, then goes to the start button, then goes to the starter solenoid.

As wired, it sends to many amps through the key switch.

Today I read about a simple fix for this, again if I'm understanding the problem correctly. In a post about a Daytona:
https://wildguzzi.com/forum/index.php?topic=101730.0
Zoom Zoom posted what I believe is an easy fix. Just unplug the original relay to starter solenoid wire (Edit) at the starter solenoid and plug it in to a new relay, then run a heavy wire from the battery to the new relay and then down to the starter solenoid. I'm am oversimplifying this.

Is this really all it takes to fix all the bikes that will get the issue?? Or is this a way to fix just certain models?

Thank you,
Tom

[Zoom Zoom]

Tom, you don't unplug any existing relay. The only thing you unplug is the trigger wire off the solenoid. Nothing else changes but when complete, you are now using your original starting system as the low amperage side of an added relay that cuts power straight from the battery to the solenoid.

John Henry

edit: Assuming the original relay is not defective, which would then need replaced.

[guzzisteve]

You need easy to understand?     It's a short cut for more direct power.  Less loom is more direct load.

[John A]

It worked very well on our 02 Stone that had a lazy starter

[Tom H]

Maybe I should have asked about this problem a different way.

What causes Startus Interuptus??????

I have read about different fixes, like adding a set of wires with a connector on each end (the one sold or free on this site), cutting a wire and replacing it, ect..

Does one fix repair all models? Does Zoom Zoom's fix only apply to one model or all?

I asked this question not just for me, but to be a thread that will help all that have had or are worried that the problem may arise. Looking for (if there is??) other fixes and why if they are model specific.

Thanks again,
Tom

[Idontwantapickle]

Maybe I should have asked about this problem a different way.

What causes Startus Interuptus??????

I have read about different fixes, like adding a set of wires with a connector on each end (the one sold or free on this site), cutting a wire and replacing it, ect..

Does one fix repair all models? Does Zoom Zoom's fix only apply to one model or all?

I asked this question not just for me, but to be a thread that will help all that have had or are worried that the problem may arise. Looking for (if there is??) other fixes and why if they are model specific.

Thanks again,
Tom

The problem arises when the excessive voltage drop to the computer when the starter solenoid engages causes the computer to turn off the starter relay. The wiring for all of this goes through the harness from the battery up to the key switch then back to the relay then on to the solenoid. As it ages or if the battery is low the problem gets worse.
By connecting a fused wire directly from the battery to the relay you bypass all of the harness and switch resistance and also remove the load from that circuit so the computer stays happy and startus interruptus no more!
Hunter

[John A]

I use the added relay on all my Guzzis,  non newer than '02 and a V65. There are more elegant ways that Roy or Wayne can probly describe but I've not done it that way.

[Kev m]

A relay is a remote control switch.

It uses a low amperage (electrical "pressure") circuit to remotely close the switch contacts on a higher amperage circuit.

But even a low amperage circuit could have insufficient amps or voltage if it's made to go through too many connections.

The starter relay gets power through one part of the circuit and a ground from another part. The two are connected when the starter button is held down.

But if there isn't enough voltage or amps when the two are connected the relay won't close the bigger switch that activates the starter solenoid (which is another remote control switch, but isn't the problem).

The starter interruptus fix installs a new, fused, direct wire from the battery to supply current to the relay without any voltage drop or loss of amps.

The key is simply determining which is the switch circuit positive power supply to the starter relay and replace that with the new feed.

Does that explanation help?

[chuck peterson]

To be sarcastic.....

It's a feature the factory put in to stay in touch w the wealthy GUZZI owners around Lake Coumo....

The bike sits after an initial purchase, maybe over the winter. come spring there is just....not....enou gh....juice...to turn it over. Short maybe 0.3 volts to excite the starting circuit.

Phone call to dealer...dealer picks up....diagnosis? Time for a new bike! This one is getting old...new bike sale...rinse and repeat.

How else do you explain a known fixable problem broadcast all over this board for 2 or more decades? Three decades! My 1990 Cal 3 had this problem...

Of course! It's a feature!

[Idontwantapickle]

To be sarcastic.....

It's a feature the factory put in to stay in touch w the wealthy GUZZI owners around Lake Coumo....

The bike sits after an initial purchase, maybe over the winter. come spring there is just....not....enou gh....juice...to turn it over. Short maybe 0.3 volts to excite the starting circuit.

Phone call to dealer...dealer picks up....diagnosis? Time for a new bike! This one is getting old...new bike sale...rinse and repeat.

How else do you explain a known fixable problem broadcast all over this board for 2 or more decades? Three decades! My 1990 Cal 3 had this problem...

Of course! It's a feature!

It's lawyers that cause features like this.

[Wayne Orwig]

On the ones that I have worked on, the starter button (and ECU) are not directly involved. Those items trip a relay contact as they should, so they are not really the issue.

What I encountered was:
Power from the battery to a fuse.
Through the harness, to the key switch in front.
From the key back to the back to ANOTHER fuse, often a smaller 15 amp fuse.
From the fuse to the relay contact for the start button.
From the relay contact  down to the starter solenoid, this wire tends to be on the small side.

When you add up the loses in the small wires, the multiple fuses, the multiple connectors, and the ignition switch, it is difficult to get the needed inrush of over 20 amps. Yes, they sometimes put a 15 amp fuse on a line that often pulls 30 or more amps momentarily. Toss in a dirty ignition switch or connector, it fails. You will hear the faint relay click under the seat, but all of the wiring can't handle that load.

I have also seen where pulling the starter solenoid apart and cleaning up the solenoid fixes it since it takes less power to pull. In fact, that was my first fix for the issue before mention of 'startus interuptus'. But, I believe the problem came back on that bike. Not surprising.

What you can do is cut the wire ahead of the relay contact, and run that through a fuse, directly from the battery. Make use of the relay that is there. Easy. Or, add another relay to the lines to feed the solenoid.

[Old Jock]

This is why I get confused with this mod

I don't know if the straight run from the battery to the starter relay (via a fuse) is on the coil side or the load side.

Logic tells me the load side BUT I see all sorts ofexplanations

For instance on here we have a volts drop causing the ECU to drop out & Wayne has just mentioned power from the fuse to the relay contact after the start button

Surely both of these are on the coil or activation circuit for the relay and not on the load side.

So the OP is not the only one on here thoroughly confused about what this mod entails

[John A]

maybe I can help without confusing myself,
85 =ground
30=battery power
86=power from switch, in this case original power to solenoid
87= power to solenoid
that's the new relay but the terminal designations are industry standard

[wirespokes]

Ok, I'll give it a try.

There are two main problems to resolve:
1. Added resistance caused by a long circuit path through multiple connections
2. The small gauge wire to the starter solenoid adding resistance

#1 is handled by a direct large gauge wire from the battery, through a fuse, to terminal 30 on the starter relay.

#2 is handled by running a larger gauge wire from 87 of the starter relay to the starter solenoid.

[Old Jock]

Thanks JohnA & Wirespokes

So if I have it right it's how I thought, a direct wire, through a fuse, on the Load circuit

The coil or activation side of the relay remains as is

At first glance though that not would cure the low volts from the ECU dropping out the relay as the ECU is on the coil circuit. In fact it would make it worse as the lower load resistance would allow more current to flow dropping the battery voltage still further.

However it's counter intuitive and probably the reason a lot of people get their knickers in a twist over it.

It's because the resistance on the load circuit results in the 0.25 Ohm coil in the solenoid being held in for longer, it would generate a weaker magnetic field, due to the lower voltage. That results in the battery voltage dipping for longer and resulting in the ECU dropping out and all the other wierd effects encountered.

I asked Roy to chime in here but perhaps he's busy doing other things, I'll take a chance and hope "he doesn't send the boys round"

Here is what I wanted him to post. One of his many sheets showing how various circuits work. This is the best expalnation bar none that I've come across and I'm indebted to him for these sheets. Once you get your head around that explanation it all becomes pretty obvious what is happening and why the load supply to the relay has to be at as high a voltage as possible and the path from the relay to the solenoid as low a resistance as possible

[RinkRat II]

        Hope this helps clarify the above posts.

       Paul B

[Wayne Orwig]

At first glance though that not would cure the low volts from the ECU dropping out the relay as the ECU is on the coil circuit. In fact it would make it worse as the lower load resistance would allow more current to flow dropping the battery voltage still further.

I know people long ago thought low ECU voltage might be preventing the bike from starting, but I thought that is generally proven to not be the problem.

Has someone recently shown that low ECU voltage IS a problem?

[bad Chad]

I'm having a starting issue with my B1100, it has not been treated for startus interuptis, so I suspect that's likely the root problem.  However I suspect my battery may be fading.  What should the sitting volts be, Im getting 12.8 with a v/meter, with ignition on but not cranking I get 12.4v.   What it has started doing it when I hit the starter I here a single noticable "clink" and then nothing.  What has worked so far it tuning off the ignition, clicking the kill switch on and off and then trying it again and bingo it starts as usual.  This just started a couple days ago, I thought it was a low battery so I gave it a boost, but it happened to day at a gas station  80 miles from home, thankfully it started using the above description on the third try, it was hot as Hades out too!

[John A]

Chad, if you add a relay it should cure it. while your battery volts is a little low, it should spin it for a start.  Who always has a fresh battery?

[bmc5733946]

On most Guzzis I merely replace the wires at 87 & 30 in the existing relay socket with 12 gauge wire and proper terminals, bringing a fused wire directly from the battery or even from battery cable at solenoid to 30, then 12 gauge straight from  87 to solenoid trigger. I then clip and heat shrink that might be exposed and tuck them away. No need to over think or complicate things, Guzzi just designed a lousy circuit that is easily rectified.

Brian

[Wayne Orwig]

I here a single noticable "clink" and then nothing. 

Almost sounds like a loose battery connection.

[Wayne Orwig]

On most Guzzis I merely replace the wires at 87 & 30 in the existing relay socket with 12 gauge wire and proper terminals, bringing a fused wire directly from the battery or even from battery cable at solenoid to 30, then 12 gauge straight from  87 to solenoid trigger. I then clip and heat shrink that might be exposed and tuck them away. No need to over think or complicate things, Guzzi just designed a lousy circuit that is easily rectified.

Yep, just a good fused power connection to the relay that is there, is all that you need.

[old head]

My Breva did the same thing until I did the MPH fix, worked for a good 10 years.  However, it reared its ugly head again, see what I did chasing this problem.

https://wildguzzi.com/forum/index.php?topic=99708.0

While cranking is much improved, I am still having the issue, even in hot weather.  Tried today, 99 outside and just a click.  The battery showed 12.0 volts on the dash after only 2 weeks from my last ride.  I dropped in my 6 year old lithium battery that had a fresh charge and it fired right up, no clicks.  Even thought the new AGM batter is only 6 months old, I think its bad as it won't charge above about 12.6 volts, dash shows 13.2 just above idle.

I did run a fused wire directly to the relay as instructed by many, and it definitely helped.  I will run a heavier wire from the relay to the solenoid at some point, and I will be looking at getting a new AGM battery as cooler weather gets closer.  This time I will get a dry battery and do it myself instead ordering one already wet.  the lithium battery always cranked until it gets about 60 and the clicks start.  Now to be fair, I haven't used the lithium since I put the AGM battery in in Feb.  It might be fine in cooler weather now that I made the changes, time will tell.

Good luck,

Old Head

[Kev m]

Thanks JohnA & Wirespokes

So if I have it right it's how I thought, a direct wire, through a fuse, on the Load circuit

The coil or activation side of the relay remains as is

At first glance though that not would cure the low volts from the ECU dropping out the relay as the ECU is on the coil circuit. In fact it would make it worse as the lower load resistance would allow more current to flow dropping the battery voltage still further.

However it's counter intuitive and probably the reason a lot of people get their knickers in a twist over it.

It's because the resistance on the load circuit results in the 0.25 Ohm coil in the solenoid being held in for longer, it would generate a weaker magnetic field, due to the lower voltage. That results in the battery voltage dipping for longer and resulting in the ECU dropping out and all the other wierd effects encountered.

I'm working on 10 year old or so memories, but I believe it was the activation circuit and not load choice l circuit which required the new fused power feed.

[Tom H]

Well this has helped!!!

Now lets see if I have this right.

Fix 1 uses another added in relay. To install: Remove the starter solenoid trigger wire from the starter solenoid. Plug wire into the new relays trigger term. and connect a ground wire to the other trigger term.. Then run a heavy fused wire from the bat. to the high amp side of the relay. Then run a heavy wire from the high amp side to the starter solenoid trigger.

Fix 2. Just remove the small original starter solenoid trigger wire from the stock/original high amp side of the starter relay. Make a length of heavy wire to go from the stock starter relay to the starter solenoid and connect.

Fix 3. Again using the stock/original starter relay. Remove both wires from the high amp side of the starter relay. Add a heavy fused wire from the bat. to the high amp side of the original relay. Then add a heavy wire from the high amp side of the relay to the starter solenoid.

For a person that may struggle with electrics, fix 1 seems to be the easiest. Why, no (UMMM right word) "relay socket" to figure out how to get the spade connector out of and plug in the new spade connector and wire.

Now fix 3 seems to be the cleanest. No relays to add. Just change the relay high amp side to heavier wires.

So the issue seems to be a wire that is too small from the starter relay to the starter solenoid, at least for the most part. Fix 3 also replaces the wire from the bat. to the high amp side of the starter relay.

Now I understand 3 ways to fix the too small wire from the starter relay to the solenoid. Got it!!! YEAH!!!!!

BUT........... Here is where I get confused again. The 40 amp power spike????

From what I understand, one of the interuptus issues, at least that stands out from all the past posts about it, is an issue of something like a 40 amp spike when you hit the starter button on the handlebar. Again from what I understand, this spike travels up to the key switch, through some wires and relays, then through the starter button, then to the solenoid. This is what causes the switches to fail.

Is there a spike through the switches???

The way I understand the fixes above. They only help from about the starter relay, not the switches. So IF there is a spike through the switches and wiring harness that leads to the TRIGGER SIDE OF THE STARTER RELAY, why would the spike happen with the starter relay???? The high amp spike, in my limited electrical knowledge, should be only on the high amp side of the relay. The trigger side that's connected with the switches should see a very small amp spike???

I'm getting there, but still a bit confused.

Thank you for your patience and help on this subject
Tom

[Old Jock]

I'm working on 10 year old or so memories, but I believe it was the activation circuit and not load choice l circuit which required the new fused power feed.

That's still feasible Kev, there are quite a lot of relays on the activation side too (depending on the model), so you may well be correct. I just was spelling out what I have seen from giving this problem some thought.

Tom H

From Roy's diagram you'lll see that the load side of the starter relay is often routed through the ignition switch, so it would see the current spike. I would doubt that the load side would also be routed through the switch (what would be the logic there?). Looking at a Centauro diagram as an example, the switch is on the activation or solenoid side.

From my understanding it's the load side that will see the momentary current spike while the 0.25 Ohm coil is in operation to pull in the solenoid. While that is happening there is heavy load on the battery and associated wiring so the load side has to minimize all resistance within it (heavier wire, fewer devices etc:).

If it has resistance it will take the solenoid longer to pull in, that time and it will in the order of fractions of a second, is suffucuent to pull the battery voltage low enough to cause all sorts of mayhem, possibly even dropping out relays.

After that the current drops the relay does nothing and the solenoid holds itself in through the 1.05 Ohm coil.

The trigger side may see a momentary VOLTAGE spike, but all relays do that.

Just how I'm reading it

[wirespokes]

^^^^^ exactly. It's like trying to put out a fire with a bunch of short lengths of garden hose. Get one length of larger hose and you'll have more than a trickle coming out.

[Wayne Orwig]

BUT........... Here is where I get confused again. The 40 amp power spike????

From what I understand, one of the interuptus issues, at least that stands out from all the past posts about it, is an issue of something like a 40 amp spike when you hit the starter button on the handlebar. Again from what I understand, this spike travels up to the key switch, through some wires and relays, then through the starter button, then to the solenoid. This is what causes the switches to fail.

Is there a spike through the switches???

The way I understand the fixes above. They only help from about the starter relay, not the switches. So IF there is a spike through the switches and wiring harness that leads to the TRIGGER SIDE OF THE STARTER RELAY, why would the spike happen with the starter relay???? The high amp spike, in my limited electrical knowledge, should be only on the high amp side of the relay. The trigger side that's connected with the switches should see a very small amp spike???

This huge power spike as I mentioned above goes, battery - fuse - harness & connectors - ignition switch - harness & connectors - smaller fuse - relay contact - harness to starter.  It is not 40 amps, because none of the whimpy wiring, switches and connectors can carry that much. It is usually under 30, or even under 20. Get a spooged up starter, and it won't pull it in when hot or wet or cold or something. But if you go back to my list above, and eliminate some steps, it is easy to go, battery - heavy fuse - relay contact - harness to starter. That gets a current over 30 amps to the solenoid to pull it reliably. Just add that wire from the battery through a fuse, to the relay. Cleaning the starter is a good idea also.

MPH made a plug in harness that did that at one time. Wonder if it still available?

[Zoom Zoom]

Wayne, the harness you refer to was made to fit a lot of CARC bikes and possibly others. I had purchased one of those for my '09 Stelvio only to discover I didn't have that connector anywhere near where I needed it, which prompted me to do what I did. I gave the MPH deal to a friend that could use it. (I doubt he ever did though, nor did he ever bother to fix the flat tappet issue. Oh well, you can lead a horse to water....)

John Henry

[Kiwi_Roy]

My take on the problem is the factory don't understand the starter solenoid, look at any Guzzi diagram, it only shows one coil.
This is the coil I call the "Hold in Coil", draws 10 Amps, it's quite weak, not nearly strong enough to pull in the solenoid.
The magnetic strength of a coil is the product of the number of turns and the current through it (10 x 300 = 3,000 Amp turns)
The coil they completely leave out of the picture I call the "Grunt Coil" because it does the grunt work, would draw 48 Amps if it was wired right
Simple Ohms Law 12 Volts / 0.25 Ohms
Its 4.8 x as strong magnetically (48 x 300 = 14,400At) as the weak Hold in Coil, It only works from button press to the time the main solenoid contact closes then it's bypassed.
The real problem is the bike wiring cannot supply the current these two coils require to do their work.
From John's post
https://ibb.co/FJzdxgc
Here is what the coils look like if taken apart, I believe both coils have the same number of turns, about 300.
The Grunt Coil is wound on the bottom so as well as being heavier it's also shorter 0.25 Ohms
The Hold in Coil is wound on top so its lighter longer winding is 1.05 Ohms
https://ibb.co/kKV3op

As Wayne pointed out you are lucky to get 30 Amps through the coils due to all the resistance between the battery and the solenoid, even an additional 5 will make a huge difference.

Notes
Does anybody think a 15 Amp fuse is appropriate for a circuit that draws 50 Amps?
No, the start button passes only about 0.1 Amps, just as much as the relay coil draws.
I don't believe its low Voltage to the ECU, SI was effecting bikes long before fuel injection.

Case Study,
My 07 Griso was starting ok but I thought why not make sure it continues to do so, here's what I found.
The start relay on this model is fed direct through a fuse but the wire from relay to solenoid was tiny, equivalent to 22 gauge I think so I replaced it with an 18 gauge.
https://servimg.com/view/19351500/9
First I measured the current with an oscilloscope and sketched it out as a base line
The red trace is how I found it drawing just over 20 amps and taking 50 milliseconds to start cranking
The Green trace shows the current increased to over 30 Amps with the new wire but look how quick it operated, three times as fast.

Conclusion
I'm not sure what it will take for the factory to wise up and fix Startus Interrupts but I can see by comparing schematics they have been thrashing around in the dark adding extra relays. it's such a simple problem once you understand it's caused by too little current or inversely too much resistance.