Starter Question

Has anyone experienced a problem with either 2006 or 2008-> CARC starter latching On until the battery is disconnected or runs flat?

I'm trying to figure out why they added an extra Start Relay to the 2008 model.

Probably an "engineering" solution to bad initial design. You gotta know - 'talian 'lectrics - been the bane of the brand for a long time. All easy to overcome with patience.

[quote="Oz1200Guzzi"]Probably an "engineering" solution to bad initial design. You gotta know - 'talian 'lectrics - been the bane of the brand for a long time. All easy to overcome with patience.[/quote

Phang told me, the Start Maintenance relay is so the ECU cannot turn the starter off again if the battery Voltage is a bit low. The additional relay keeps the starter cranking as long as the button is held.
Seems to me like a hardware fix for a software problem.

I remember in 2008, Guzzi issued a technical bulletin for a certain VIN range of Stelvio, to remove the "Maintenance Relay" because of the latching problem.

Found it.

Dear  Dealer,
a possible starter button jamming could result in the vehicle stalling, due to the starter motor
being  continuously  powered  and  possibly  causing  a  short-circuit  of  the  motorcycle  main
relay.

To  avoid  this  failure  you  must  remove  the  relay  (part  no.  AP8124869),  it  being  missing
does not compromise in any way the vehicle functions.

It can be removed from all vehicles during pre-delivery inspections or when the vehicle first
comes in at your workshop. No labour costs shall be reimbursed for this service.

Relay removal procedure is described herewith.

The relay is installed at the front of the fairing, on the right side of the bike.

CAUTION: in this position there are 2 relays; you shall remove the one closer to the fuse
carrier, the light grey one.

I wonder why this advice was for the Stelvio only?

That's the one I was talking about, thanks

I just compared the 2008 GRiSO and Stevio wiring diagrams, specifically the way how Start-up Relay, Maintenance Relay, Start Button and ECU are connected, I don't see any difference between the two.

Judging from the Guzzi bulletin instructing dealers to remove the Maintenance relay from the affected Stelvio. If I may venture a guess, firstly, it's only happened to Stelvio, it's only affecting the very early batch, it is something that a quick replacement of relay won't solve but an absence of Maintenance relay will.

Leading me to think of a bad batch of wiring harness were fitted to these bikes. Of course, a sticky Start Button and/or a sticky Start-up Relay will cause latching problem too.

If i remember correctly when the ECU measures low voltage cancels the start process. I dont remember the minimum voltage value...

The ECU can measure voltage lower than what the battery actual has, due to voltage drop to both :
- the power ("hot") wire that feeds the start circuit. Some of its lenght is common for all electic circuit, its known that the wire size is too small for the start relay-solenoid part, the same and some more current goes through the same sized wire that feeds the relay... This part has less lenght so the voltage drop from the size alone is smaller, but goes through some connectrors that adds to voltage drop.
- any ground ( - ) connection. The ground path is common to solenoid, starter, all electrics and... ECU. Any dirty/loose contact adds to voltage drop, and the ECU cancels the start.

Removing this relay may result in need for more often contact cleaning/checking or repositiong the groud connection to the engine.

Sory if those makes no sence, I'm too tired atm to try expressing in English... 'Αμα προτιμάτε Ελληνικά θα'ναι πιο εύκολο (would be easier if you preffered Greek)

I hope we didn't further confuse the confusing topic with our second language  

如果用中文的話，我會表達得比較好  

Now, you lot are bragging with your language skills!

Many years ago, there was a plug-in fix of a diode and capacitor. I don't know where this went, but it was a kit for CARC Guzzis. I believe this was to fool the ECU into having sufficient voltage to effect a start.

The diode and capacitor, held the voltage up for the ECU, so that when the volts went low on starter motor engagement, the ECU would not suddenly decide there was not sufficient voltage to in fact start, and thereby abort the start cycle.

I suspect (though in no way verified) that this is now built into to loom/ECU/Dash to ensure a start is consistent.

Just another work around for poor design.

There seems to be many of these coming out of Mandello De Lario! We, of the great unwashed, have worked out the short-comings of said designers, and have made or purchased our own "Startus Interruptus" kits.

'Talian 'Lectrics eh?

Phang wrote:

I hope we didn't further confuse the confusing topic with our second language  

如果用中文的話，我會表達得比較好  

Mais pas du tout!! Tout est bien clair comme l'eau de source...

I suspect the ECU and dash are farmed out to a sub-contractor, perhaps the Guzzi designers are just as helpless as the owners otherwise it would be a no-brainer to fix the start signal in logic by having a lower Voltage set-point while cranking instead of adding hardware.

Oz1200Guzzi wrote:

Many years ago, there was a plug-in fix of a diode and capacitor. I don't know where this went, but it was a kit for CARC Guzzis. I believe this was to fool the ECU into having sufficient voltage to effect a start.
'Talian 'Lectrics eh?

Is this the diode and capacitor shown in the wire to ECU pin 4 on some models
Called the "Presetting or Predisposition Diode"
Not all CARC bikes schematics have one.

I would have thought the ECU measures the Voltage to pin 17

Sorry, I only speak English and Kiwi (I'm somewhat rusty on that)

Year Roy, that would be it. I believe earlier models had a plugin for this, I suspect the later models had it built in.

Say after me: Un Zed, Bro