Gen warning light always on?

discussion about the 750 Sport and '89/'90 900SS, which share many mechanicals with the Paso series
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Dukiwi
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Joined: Sat Dec 19, 2015 6:06 pm
model: 750 Sport
year: 1989
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Gen warning light always on?

Post by Dukiwi »

Hi,

My battery dash light is always on. It's a new bike so I'm not sure if this is new or an old issue. I've got a few things to check today; standard charging system diagnostics.

In the meantime I was looking at the 750sport and 750paso workshop manuals and they both say this:

Gen. Warning light. It must light up when the system is fed by rotating the switch key and must remain on either if the engine stops or is running at any rpm.

Am I reading that right? Always on? Off indicates an issue? I have a mate with a an old Ducari GT and his charge light works in this manner. All my other bikes have had the light come ON to indicate charging issues.

Thanks,
Rich
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Derek
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Re: Gen warning light always on?

Post by Derek »

Connect a meter across the battery and start the bike. If the voltage rises to around 14V or so then it's charging fine regardless of what the lamp does.
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Mc tool
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Re: Gen warning light always on?

Post by Mc tool »

AND some of the early replacement units didn't have provision for the charge light so I guess individuals may or may not wire in that light some how , but as Derek sez put a volt meter over the battery , if its charging and its still pissing you off take the bulb out :)
I wish I was young again............Id be heaps smarter than last time
Dukiwi
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Joined: Sat Dec 19, 2015 6:06 pm
model: 750 Sport
year: 1989
Location: New Zealand

Re: Gen warning light always on?

Post by Dukiwi »

Thanks for the tips. Yes, I checked the charging voltage. 12-13v at idle and 14 or a bit more at 5k rpm. That seems fine. After that the light has gone out. Odd, but all good I guess.
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higgy
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Re: Gen warning light always on?

Post by higgy »

not at all fine.............not even close
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There's no problem so bad that a little fixing can't make it worse! : )
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Dukiwi
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Joined: Sat Dec 19, 2015 6:06 pm
model: 750 Sport
year: 1989
Location: New Zealand

Re: Gen warning light always on?

Post by Dukiwi »

Not even close? Care to elaborate and help me out a bit here? I would've thought 14v is good. It doesn't go much more than .1 or .2 higher. Not high enough to lead me to suspect a regulator issue. Unless I've been misled on the optimal voltages but that's what I have found mentioned on these boards when I searched before posting.
Mc tool
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Re: Gen warning light always on?

Post by Mc tool »

Old elecrtix on these ducati's ( Paso's too ) are real good at being bad when the get a few years under their belts ( change them too ). Pays to give the whole plot a good going over to help prevent strandings , I think that's what Higgy's meaning , is just because its going now doesn't mean it will keep going ............ actually the fact that it works now is all the proof you need that it will crap out , oh yeah ..... they never do it at home either
I wish I was young again............Id be heaps smarter than last time
Dukiwi
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Joined: Sat Dec 19, 2015 6:06 pm
model: 750 Sport
year: 1989
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Re: Gen warning light always on?

Post by Dukiwi »

I hear that! Thanks.
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higgy
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Re: Gen warning light always on?

Post by higgy »

Hamish has the idea. On my 907 with dual headlights I had the stator rewired as a two wire with leads that are long and go all the way to the shendengrin mosfett regulator now located at the rear of the bike. I also installed a dual relay setup to supply the headlights. I now get 14.4 volts at the battery once the regulator warms up. The only time I see less across the battery is when cold or the fan runs with the headlight is on while at idle . then never less than 12.5 and increasing rpm to 1500 it comes right back to 14.4
Ducati,making mechanics out of riders since 1946
There's no problem so bad that a little fixing can't make it worse! : )
If it ain't broke keep fixin it till it is
88 750
90 906
92 907ie
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