Battery charge light

[Martin Barrett]

In the What did you do today thread I predicted that I'd take the Guzzi to work this afternoon. Well I was almost correct I set off but the charge light didn't go out. It normally goes out straight away. It was burning nice and bright. She had cranked over okay and started first time despite being stood outside for 6 days.

 

I decided that discretion was the better part and returned home and took the car to work

 

On my return I've started her up and the light went out. Went and grabbed my helmet to have a quick spin around the block and on restarting the light went out and then came back on, went out again and came back on, rode down the road rode went out briefly as the revs hit 4grand but has stayed on since. All other electrical functions appear to be working.

 

I've done brief search and tomorrow. I'll be checking the yellow wires connectors under the front of the tank. The tightness of the battery terminals (though I'd think they'd be fine as it cranked no problem). I' don't think this would be a relay/fuse issue, and reaching for a multimeter to check outputs etc (clueless).

 

Any hints would be appreciated.

 

Following Dlaing and Felix having to replace their rectifiers/regulators and Felix frying his alternator and also Antonio saying he's replaced his as well I'm not sure what I'll find

[Baldini]

...reaching for a multimeter to check outputs etc (clueless....

 

On DC Volts (

 

KB

[dlaing]

On DC Volts (

 

KB

81257[/snapback]

The shop manual indicates 14 to 14.6V

But at idle and low RPMs you will readings in the 12.x to 13.x range.

Depending on the load (and my memory) you should see 14V at about 2500 to 3000RPMs

If you don't see 14V by 3500RPM, I would think something is wrong.

If you see over 14.7 Volts, that could also indicate something is wrong.

[emry]

Check where your stator coil plugs into the harness. Mine was melted when i finally noticed it; still didn't have a charging problem but I am sure it was not far away. Should be within 3 or 4 inches of the stator on the front down tubes. The plastic that is around the connectors was melted beyond belief. Dripping...

[felix42o]

Yeah I had checked the rectifier, blamed that. Ended up being that the rotor was out of round, and was causing a short every time it contacted the stator, judging by the rub marks on both components. Specs between the two yellow leads should be around .3-.4 ohm as I recall, with no resitance between yellow lead and ground. What a pain in the ass-still waiting on a alternator unit.

[docc]

Dlaing's figures for the output will determine if you regulator is up. Checking connections and fuses first is always good medicine.

 

Last year my warning light and the voltage readings led me to a new regulator.

[Martin Barrett]

Progress report:

 

Cleaned up the yellow connectors as recommended, did seem quite dirty. Whilst fishing around there I found the red/green wire with what appeared to be melted crimped end tucked behind the frame tube. I then found a pair of red wires coming up to this point with a similar connector.

 

 

Picture shows them pulled out into view.

 

Check of wiring diagram confirms that they should be connected.

 

 

Picture lifted from Carl's splendid schematic

 

Started to rain so I've not yet reconnected them, now where my silver foil and sticky tape - bodge point here I come.

[luhbo]

Before you connect them, do check where they go. I'd not rely on colors and schemes and such.

For me the terminals don't look as if they should be mated.

 

Hubert

[stogieBill]

I'm not the most comfortable guy around electronics, but I think the connection looks to be the correct one based on the schematic (green/red to double red). Unless there's other loose (unconnected) connectors, I'd go with the reconnection.

 

Of course you've got to wonder what caused the separation to begin with

 

Good luck

[Guest Nogbad]

Of course you've got to wonder what caused the separation to begin with

 

Good luck

81303[/snapback]

 

Look out in case a heavy overload caused the connector to melt in the first place. If the rectifier has gone down closed circuit you could get a short across the battery set up. Mind you, shouldn't there be a big main fuse to protect against such an eventuality?

 

(I hope I'm going to be able to award another point very soon.....)

[dlaing]

Just so you are sure, the red wires lead out of the regulator and connect to the red/green wires, which lead to the number 3 fuse, and then to the battery.

The melting of the connectors is disturbing.

The 30A fuse should have blown.

The regulator may have failed.

After you reconnect the wires be sure that you do not get more than 14.7V at the battery with engine revved up.

More so than Volts, amps will fry the wires.

Do you have any accessories like hand warmers, fog lights, high output headlight, etc.

[Martin Barrett]

The red wires do appear to be coming out the regulator, so I'm happy that the schematic matches the actual wiring.

 

All the fuses appear to be intact.

All other electrics appear to be functioning as normal.

I don't have any additional electrics on the bike.

I assume I'm running on battery power since I started it yesterday. Run less than a mile and 4 starts no discernable loss in cranking power.

 

I have suffered one blown fuse about 6 months ago for no apparent reason.

 

The bike has lived outside for the last year as my garage is full of other crap, it get used all year and not washed down as often as it should, so it suffers the ravages of salt etc.

 

My one concern is this the cause or a symptom.

 

I will acquire a Multimeter tomorrow so can test as recommended.

 

I hope it's just a victim of corrosion which may have caused the melting as the part rotted away leaving a narrow contact point which obviously got hot.

 

Thank you for all your help and suggestions

[felix42o]

Just for the record, the entire time I've messed with this problem, the only fuse to have blown has been the one for the instrument lights. 30A number three has been a trooper, as troubling as that is. Cost me an extra rectifier. <_>

[emry]

I would repair the connection and fire it up and see what the charging system does. In my case the connector was failing but my charging system was still functioning adequately. Lets not for get as a connection corrodes the voltage drops which causes the amperage to rise, thus melted connector. Maybe you will be lucky.

[Martin Barrett]

I would repair the connection and fire it up and see what the charging system does. In my case the connector was failing but my charging system was still functioning adequately. Lets not for get as a connection corrodes the voltage drops which causes the amperage to rise, thus melted connector. Maybe you will be lucky.

81419[/snapback]

 

That's my hope and plan of action.