charging current light does not light up / starting issues

[dowieze]

When starting the V11 the charging current light does not light up.  I have a new battery and the voltage, when the motor is off,  stays  12,72 V.  I think the generator is working.  I have since a while starting issues.  What can be the cause? 

[docc]

Hello, @dowieze !

What year is your Le Mans (as the wiring changed from early to late V11)?

[Weegie]

Don't have a V11 got a Sporti they are sort of close at least the earlier models.

12.72V sounds like it should be sufficient to crank the engine

 

When you say starting issues what are the issues?

Does the bike not spin the engine on the starter or is it slow to spin, or does it start to spin then stops?

If it doesn't spin on the starter do you hear a click or clicks or nothing at all?

Startus Interruptus?

A common and much debated topic, just google "Guzzi Startus Interruptus" being brief the factory made an arse of the starting circuit and there are fixes.

Problem with the starter?

That's not so common but certainly not unknown

 

or does the bike not fire?

 

If the battery is at 12.72V it does sound like the bike must be charging, checked the bulb on the charge warn light?

I'm assuming the battery is good, many will read a good resting voltage but when a load is applied completely collaps

 

Just some mad first guesses from an incompetent, better minds will be along shortly

[dowieze]

The V11 is from 2002.  The starter is realy slow.  After a few attemps it starts with a dot of trottle. It just seem he will not start at all.

[Weegie]

Doesn't sound like Startus Interruptus then

Perhaps the starter motor is needing some love or the brushes are getting worn, but as I've never had to that I don't know what's involved

One more thing, I haven't heard of it so much with Guzzis but is quite common on Ducatis, the large battery lead to the starter can degrade over time and the starter doesn't get the full voltage so the starter spins slower

If there is somewhere you get easily get the battery load checked or test with another battery to totally rule the battery out, it's unlikely but again not unheard of.

Wait until @docc comes back as he's a lot more familiar with these models than me

John

[MartyNZ]

Until an electrical expert comes along, here are some things to do. Even if it doesn't fix your problem, it is still good basic maintenance.

1. Undo and clean the negative cable connection to the gearbox. Bright metal to metal contacts. Assemble with grease/ Vaseline/ DowCorning4 oozing out as you tighten the bolt.

2. Do the same to the battery terminals, and starter terminal 

3. Make sure the regulator is grounded properly. You may need to add a grounding wire.

[docc]

+1 on the grounds first, @MartyNZ !

@dowieze, once you attend to the grounds, we can take on what is next if your V11 still makes trouble for you . . .

[Rox Lemans]

Both mine do that. The woes of a high compression motor.How old is your battery? I normally have to swap mine every 2 years. These alternators are known for being a little weak . I've been told there's some internal clock that saps the battery but not sure how true that is. 

[Lucky Phil]

52 minutes ago, Rox Lemans said:

Both mine do that. The woes of a high compression motor.How old is your battery? I normally have to swap mine every 2 years. These alternators are known for being a little weak . I've been told there's some internal clock that saps the battery but not sure how true that is. 

It's the ecu. There's a hot wire through fuse 1 to the ecu. 9.8/1 comp, not that high really.

 

Ciao 

[docc]

@dowieze, here is the location of the critical main ground from the battery negative/earth terminal to the back of the gearbox on the right, behind the seat latch:

If the starter cannot ground back to this point, it will destroy the wiring harness trying to start . . .

Also, let us all be aware that the starter motor, itself, grounds through its mounting bolts. It is very important that these bolts, their washers, threads, and surfaces between the starter motor and mounting surface are clean, connected, and sealed from corrosion.

[docc]

2 hours ago, docc said:

+1 on the grounds first, @MartyNZ !

@dowieze, once you attend to the grounds, we can take on what is next if your V11 still makes trouble for you . . .

We will talk, next, about the relays since you have said the "charging current light does not light up."

Then on to the Ignition Switch.

[Chuck]

FWIW, the Mighty Scura's charge light only works during certain phases of the moon. It has never been a problem.. I thought they all did that?

[gstallons]

These lights are a luxury not a necessity

[docc]

33 minutes ago, gstallons said:

These lights are a luxury not a necessity

I mean, true, but ignore them at our peril. But, also, very challenging to understand how they are wired in and what various states of illumination, or not, might indicate.

That @dowieze has "starting issues" as well, may make the light absence helpful to the troubleshooting . . . .

[footgoose]

On 9/29/2021 at 4:01 PM, MartyNZ said:

Until an electrical expert comes along, here are some things to do. Even if it doesn't fix your problem, it is still good basic maintenance.

1. Undo and clean the negative cable connection to the gearbox. Bright metal to metal contacts. Assemble with grease/ Vaseline/ DowCorning4 oozing out as you tighten the bolt.

2. Do the same to the battery terminals, and starter terminal 

3. Make sure the regulator is grounded properly. You may need to add a grounding wire.

I want to second this post and especially the "it is still good basic maintenance." part. Actually to the point of putting this in the top 3 items to address for new owners. I watched and listened to forum members and when I finally got around to it (regulator/rectifier went bad) I did this: cleaned and brushed/scraped/sanded all surfaces from batt to case (see docc's post) THEN added another wire (same as batt ground) from case forward to a bolt on the frame, and then another from there to the R/R. I used DeOxit and star lock washers at all points. (made me feel better)  Potential grounding failure at these points are known and should be addressed first.