Flickering charge light

[lemppari]

Been having strange momentary dim glows awhile when riding. Trying different gears at same speed didn,t have any effect on the phenomena. The charge light comes on for a few seconds and then shuts off. I rode 850 km's yesterday and didn't get stranded, so I suspect there's nothing fundamentally wrong! When the engine is running stationary I've measured 14 volts at 3000, but as I don't have a voltmeter connected, I can't tell what is happening up in speed.

 

I will however connect an extra ground to the regulator cover as described here elsewhere,but could this be just false ground in the charge light circuit? Every now and then, when i switch the ignition on, there's no charge light but after the engine has run a few seconds, shutting off and switching on again, there it is. Seems it get worse when riding through a rain shower and the light is much brighter then. I will also take the tank off and check all connnections more thoroughly. I know that I'm the antithesis of an electrics wizard but I WILL NOT CAVE IN! Any suggestions apart from letting the local Guzzi repair shop do it?

[lemppari]

Come to think of it, why not start with the simple alternative before going to the complex ones. I'll change the battery first, it is coming of age on a RM anyway!

[lemppari]

Magical mystery tour continues...Rode to my garage and descended upon the bike armed with a multimeter. Ignition off, the reading frm battery was 12.8 volts, at idle 13.7ish, at 3000 revs and up 14.2, steady. The reading from the black cable going to the reg same 12.8 V. After rigging the auxiliary ground cable from reg cover to frame the reading from idle onwards was a constant 13.9 volts!? And the generator warning light disappeared altogether until after a test ride when switching off and on again.

 

Is the white cable besides the black one for the gen light? I think I'm getting the odd things happening to the light every time I'm fiddling with the black and white connector and furthermore it gets it's share of air flow at speed. That is when the light starts flickering, anyway.

 

It sure is not fun being electrically impaired.....

[Kiwi_Roy]

You may have cured the problem by adding the ground.

Yes, the white wire is for the light, one side of the lamp is supplied with 12 Volts from

the headlight relay, the white wire pulls it to chassis with a transistor.

Roy

[lemppari]

Clutch done at long last, I was coming back home from the first test ride and guess what, I got the charge warning light again. On and off, no logic, no relation to revs used, not even speed. Ony possible hint would be that it started at the seaside where it was more humid and cold.

 

Well, tomorrow it's back to garage with the voltmeter and going through all connections. I must admit I'm growing weary of these constant gremlins. Didn't mind so much of the clutch rehearsals, but this thing with electrics drives me mad. As I've said before I'm electrically challenged or downright handicapped.

 

So, last time I made the extra ground for the regulator but the problem must lie somewhere else. If it where a shortcut, it would blow fuses, wouldn't it?  Let's start with connectors in and around the main lamp and go further from there.

 

I have never had a bike opposing so heavily to getting on the road as the Rosso Mandello.

[luhbo]

Put it in an ofen at 100°C for one or two hours. This may cure the problem for some time. These regs are insufficiently sealed, after some years moisture gets inside and does strange things to the components. The annoying thing is that you can't rely upon the red light. When it comes on as on your bike now, the charging usually works - or not

 

Try the ofen. In case this helps you can still try to seal the gap or cracks between the housing and the green potting compound.

 

Hubert

[lemppari]

Thanks Hubert, your suggestion sounds perfectly logical to me. Last summer I rode over 200 km:s in rain with the intermittent charge light and I'm told that 30-50 km:s would kill the battery without auxiliary power from the generator.

[luhbo]

You'll already have salt and/or acidic elements inside which won't come out again. You better keep your eyes open in case a new one might appear on ebay or the like.

Good luck.

Hubert

[docc]

Good advice to dry out your regulator. And I did not know there is a transistor in the charge light circuit. Where would that be, Roy?

 

Something simple to check would be the 30 amp fuse. They commonly melt, or a blade burns off, without blowing the fuse.

 

And Roy's mention of the relay always cast some aspersion there: Make sure you are using quality relays that are not failing your electricalism! Swapping in a fresh, high quality headlight relay is simple and worth trying.

[Gio]

Your measured voltages look ok lemppari ... and similar to what I have measured on many occaisions - I have experienced what you describe for more years than I can remember and never had a problem with the battery ... so I have concluded that the charge light exists in some kind of alternate universe and no longer worry about it. Adding the extra ground did not change the behaviour in my case.

 

The oil light would be a different story ...

 

Gio

[lemppari]

Take this morning for example. After spending the night in front of my house door, the Thing didn't show charge light when turning the ignition on, but flickered slightly when I took off. Go figure!

 

Sent from my RM-821_eu_finland_207 using Tapatalk

[GraeV11]

I am with Docc on this one. Pull that fuse and have a good look. I had one with a fracture on one leg that gave the same symptoms. 

[luhbo]

 

... Pull that fuse and have a good look...

Hmm, that makes me think, too. Some weeks ago I had a dead battery after 3 hours in heavy rain (red light on). Swapping the regulator helped, but just some hundred Km later the light came on again, no charging. This time, because the reg was changed already and the bike not fully packed (you cannot rally every day) I checked the fuses and found the big one blown. So now, what if ...

 

Hubert

[Kiwi_Roy]

The charge light is turned on by the regulator switching a transistor (brown wiring)

I'm not 100% sure but I think it turns off when the battery is up enough that the regulator starts skipping pulses.

 

Often the 30 Amp fuse will melt due to a bad connection (loose fuse clips) rather than blow due to too much current, look to see if the plastic is discoloured.

 

[lemppari]

Had a nice long test ride yesterday. Weather was warm and dry, not a single flicker that I would have noticed before riding back home via a 35 km archipelago road when we met chillier and more moist sea air and bingo, charge light started it's dim flickering. When I rode back inland and stopped for groceries the flickering stopped for the rest of the ride. My money is still on inadequate sealing of the voltage reg.