Electrical Failure

Fat GRiSO had a hissy fit today somewhere between bum-fuck nowhere and where they insert the big hose to give the world an enema. All was well until pulling up a hill, it cut out , dead , dash doing funny things. Snatched in the clutch, engine is dead.
Key Off, ignition on, dash lights up normally, press start,  click from starter , dash blanks out. After several attempts with the same result I hitched a ride into the nearest town, Gympie. Purchased a new battery, paid a local for a ride back to the bike.
Installed new battery, key on , dash lights up normally. Press start.... success, engine runs sweetly. Toggle display to volts, 12.3 running , shit.
The fellow who gave me the ride offers to follow me to town. Ok let’s go.
Monitoring the volts I have an idea, pulling over I disconnected the 2 headlights to help save the battery. Low and behold, it’s charging now, and all the 1/2 hr ride to town.
When safe in town I reconnect the headlights with bike running, alternator drops offline, disconnect the headlights and alternator charges again WTF
Did some searching, the headlight relay also is used to excite the alternator.
Does anyone have an idea what is going on here ?

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Has Fat GRiSO for spotlights? If so they are a known problem point with shorts but they usually blow the fuse. Charging being connected with the headlight being plugged in is weird!

How about if you flickit on to high beam? Does that make any difference?

Pete

I didn’t think to try that Pete, but it does work fine with the lights unplugged???
I’m going to try changing relays out tomorrow

sure looks like a dark and gloomy ol' track there Ron..... I can see why you had all your lights burnin!

Waterbottle I had the same problem when I got stuck in the Alps two years ago (alternator wasn't charging). I ended up taking off the tank on the side of the road and cleaning all the connections.

I thought that the problem was one of the relays but it wasn't. I think that you need to take off the tank and clean / scrape/ sand the small connector on the wires that goes to the dash from the alternator. As far as I can make out this is the exciter for the alternator. Also check the main heavy wire to the alternator is corrosion free, this was clean and making a good connection on mine but the small connector that runs to the dash was corroded but at the time I thought that couldn't have any thing to do with the alternator not charging, but I cleaned it anyhow out of desperation on the side of the road with my missus looking at me in a state of nervousness!!

When I put it all back together after cleaning every corroded fuse / connector and relay that I could find, HEY PRESTO she was back charging. I was convinced that it was a badly corroded relay but when I returned home and checked the wiring diagram it was a relay for the fuel injection and didn't make any sense to me.

I am now convinced that it was the cleaning of the small connector to the dash which I think is also the EXCITER wire for the alternator.

Check it and see if you have any joy

Unlikely to be exactly the same, but that sort of thing happened to the V7C once - tacho & speedo fluctuated wildly & all the dash lights cycled & recycled & a few ks further on, the bike stopped. Flat battery. GRiSO content - a red GRiSO going the other way to work looped around the the off ramps ( Pac Hwy just north of Cundletown) to check on me. Turned out to be a blown & burnt out connector between the reg/rec & the main harness - so no charging & a flattened battery. Apparently a known problem. Solution was to cut out the connector and the burnt wires & join up the wires without a connector. It appears likely that the haywire dash behaviour is an indication that something severe has suddenly interfered suddenly with the smooth flow of current. Pity that grey smoke can't be observed directly. Good luck with that, Ron.

I may be wrong but I suspect one of your lights may have a near short, you don't notice it in the bright sunlight. The Light logic relay supplies excitation to the alternator, since it's shorted out the battery goes flat and eventually cuts out. Unfortunately by the time it goes flat you don't have enough power to re-start again.

It is a well known fault on the Stelvios, the spot lights short out and the batteries go flat.

I would wire a 10 Amp fuse into each of the headlight wires from the dimmer switch then if you get another short you will only lose H or L beam, not both at once.

It's similar in a way to the belt braking, goes flat after 20 minutes or so without warning.

It would be useful to know if the lights are going, some sort of an idiot light across the alternator excitation supply.

Being a Guzzi the wiring is a bit weird.

[You must be registered and logged in to see this link.]  Thanks to Carl

Kiwi, Thanks for the idea to fuse the lights individually, will definitely get that done soon.
More work today, Problem Solved, Woo Hoo
Put the old relays back in , Still no go
Pulled Tank off, Checked alternator exciting plug, tight connection and clean.
Checked Main power cable on alternator, found I could move the cable lug a little bit side to side, but still tight enough that I normally wouldn't have worried about it.
Removed cable from alternator and cut heat shrink off to check wires for burning, all found satisfactory.
I then check tightened the alternator post nut and found it was loose, tightened about 5 or 6 flats to firm it up. It has a shitty plastic insulator on this post so I was careful to not crush or shatter it.
Re taped the cable, assembled everything, Started Engine.................
We have Lights , We have Charge 14 Volts, Hi beam Low Beam, all Good.        
Thanks everyone for your Help, Especially Bahamazoo ( Pat ) for his help and hospitality.
Have a Great 2019 everyone

Ha, no problemo Ron, happy to fetch beer and make coffee....

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next time you're down, let's try to have 2 bikes that run so we can actually go for a ride    

See you at the Budgie!


ps: thanks for the lube!!

Never go in dry Pat

So it turned out to be the main power lead loose?
Do you think that might be a common fault, does it heat up and shrink away from the bolt or what?
Is there some way we can capture the wire lugs between two nuts rather than nut and insulator.
Any pictures?

Classic - 'talian 'lectriks.

As with all things, sometimes you need to go look, check, tighten - spend an afternoon doing it, have a beer. Knowing it "won't" let you down is always a good thing.

Roy, probably - assuming there is a consistent interface with the bottom of the stud and where is cast into the insulator (plastic/bakelite?). A flat washer (that is indeed flat - perhaps machined flat or at least spent a bit of time on the linisher) would work, maybe in brass or something silver plated, would be the go. Probably retain the spring washer on top of the lug, then the nut.

Some very weird stuff here, and I haven’t worked out how it works yet, but I have worked out that there are 2 relays for the headlights.
The 1st one is called the Light Logic Relay,  # 5  in the wiring diagram, it pulls in to provide power to Relay # 65 which is called the Low / High Beam relay.
# 5 Relay also supplies power to the Exciting wire for the Alternator
# 65 Relay is triggered by the High Beam switch.
#5 Relay is Pulled in by the ECU on start up. ( That’s how I Think it works )
I think this particular problem was caused by the loose Base nut (#2 in photo ) which caused a resistance in the main supply to the battery.  It would charge the battery with no load other than the injection, coils , tail light etc, but as soon as I plugged in either headlight, the # 5 relay would drop out , hence no lights or charge.  
I did find some info on wild Goose from Cunuck ———— where he fitted another relay and a Red warning Light. Red light on at key on, when powered at start up the relay opens to switch the light off.
Also noted was the Shitty piss poor quality terminal crimped on to the 2 main power wires at the alternator, this will also be replaced with something more substantial.
1st Photo is of a Guzzi alternator I found on google. It was the Base nut that was loose on my Alternator.
1:  Plastic spacer/ Insulator
2:  Base Nut
3:  Terminal Lug Nut
4:  stud

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I think you are right, if the wire was not making good contact with the bolt it may have heated up and melted the plastic of the spacer making it loose. Someone riding with you probably would have noticed your light flickering.
If the internal wires are terminated directly to the bolt (not reliant on the nut) it might be best to put the external wire between two nuts locked against each other rather than between nut and plastic washer, I think you know what I mean.
I'm sure someone else will have a problem soon enough. Good on you for analyzing the problem.
Yes, the relay 5 excites the alternator once the engine is running.
Your schematic is obviously different from the one I have.

Kiwi, I pulled the modified diagram off Wild Guzzi too. Apparently the original was incorrect

Is there a volt meter on dashboard of Stelvio?
Edit -My bad I can see now there is.

Stubbie wrote:

Is there a volt meter on dashboard of Stelvio?
Edit -My bad I can see now there is.

Stubbie, yes there is, but it's a pain in the butt to monitor. I'd rather have it on Trip meter. A big red light would be more practical. No Light = All Good, Red Light = Not Charging

Just found this. Not sure if youv'e seen.
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We had problems w/early ones melting the plugs on the bulbs, I put a second set of relays to them, one for high, one for low. Also used ceramic plugs like cars had. Never an issue later. Sounds like you found the issue on yours. Lots of load going up front.

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I have been using the Charging Indicator LED that I mention in the link that I posted above for the las two years and it works great. I hadn’t been using the bike for about a month in the summer and when I checked it the amber light was flashing to alert me that she was loosing the charge, it is normally flashing green when all is ok.