Flickering charge light

[Kiwi_Roy]

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.

You are probably right but just for the hell of it check your two yellow wires for tight connections.

Take the cover off and check the connections where the yellow wires are soldered to the windings, mine at 80k km were holding by just one strand.

The sea air being a little salty may be causing the light to track to ground, it has + 12 Volts on one side.

 

Of course Luigi put the regulator in the best spot, exposed to water and road salt, the Aluminium to Steel in a salty environment is certain is  to corrode, all of the current to the battery has to make it's way back through there.

If you don't have a ground strap add one, the regulator has a black wire from it's case back to the battery but that is not man enough for the job.

[lemppari]

Extra ground wire has been added last autumn, so bad earth should not be the cause of the light show. But yes, I haven't checked the generator end of the yellow wires.

I had a funny experience with my LM I last autumn, I lost all current gradually, first  to go was beam, then went the blinkers, and one km before my garage the bike died. I have a Silent Hektik regulator screwed inside the gen cover with sturdy nicely secured connections, only somebody hadn't connected a wire properly in the connection. Out went all 32 amp/h of electrons from the battery. Easy fix for once,though...

[JBBenson]

I added a fat 6 gauge ground from my regulator to a screw on the timing case, sanding clean all connections. Bike definitely cranks better now. 

 

Thanks to Kiwi_Roy.

 

j.

[docc]

I added a fat 6 gauge ground from my regulator to a screw on the timing case, sanding clean all connections. Bike definitely cranks better now. 

 

Thanks to Kiwi_Roy.

 

j.

Wow: 6 gauge - that's kind of a small welding cable, yeah!

[luhbo]

Well, some additional weight on the front wheel won't hurt. It makes the steering more reliable.

You know these fat, high bling clear coated speaker cables, which, according to the HiFi geeks at least, can even turn Heino into music?

 

Hubert

[lemppari]

A new phenomena occured. I rode the bike home and  left it running on idle. The charge light shone dimly and I desided to see what happens if I switch off the lights. The charge light glow grew instantly brighter and switching the lights back on dimmed down the charge light. Repeated switches gave same result......

 

??????........

[docc]

OH, my! Grounding through the wiring harness?

 

Check, clean, and reattach the main ground cable to the back of the gear case. Use a "star" washer to cut in a good contact.

[Kiwi_Roy]

The charge light picks up 12 Volts downstream of the headlight relay very close to the spot where the regulator gets a Voltage reference.

At that point the regulator holds the Voltage to about 13.8 Volts but the battery is a good half Volt or more higher depending on the headlight draw..

So when you turned off the headlight the Voltage would shoot up by at least half a volt, more if you are running a larger headlight.

 

This may not be the explanation.

We don't have light switches here so I can't duplicate it.

 

Check the ground as Docc says, I know of several bikes where it was under the seat release lock leading to a melt down on cranking.

[lemppari]

Put a Cetek battery charger to fill the battery with smoke yesterday evening and there was absolutely no flickering in the dashboard when I rode 60 km's to work this morning. Could it be that all these symptoms are caused by a battery past its' prime time? I don't recollect ever changing the battery and I've had the bike 7 yrs .

[luhbo]

It's a long time, 7 years, but for a Hawker not really extraordinary. It should be able to start the bike and provide a reasonable buffer for voltage spikes and ribble in general (in an automotive environment), that's more or less all for what you need it. Everything else is managed by the alternator/regulator combo, to my understanding at least. So, I'd say the battery probably's not your problem.

What have you done with your regulator in the meantime? Are you sure it is ok now? Have you measured the battery voltage during yesterday's control light show?

 

Hubert

[lemppari]

My garage is some 5 km's from my front yard and all my tools are there, so no, I couldn't measure the amount of smoke in the system. And yes, the regulator is what I believe to be the villain in this story.

 

We're coming south in a week's time to holidays and as I'm riding down past Braunschweig I might as well visit S+D and buy a new one. Or maybe if Mike at HMB might have one, I don't know.

[lemppari]

So, coming home from work still without a single flicker after charging the battery last evening, I went and connected my voltmeter to the battery terminals. Steady 12.75 when not running. Idle without lights was the same, but at times undulating between 12,5 and 12,9. Switching the lights on dipped the voltage appr. 0,2 Volts, undulation as well. Steady 13,9 V at 3000 rpm, 14,2 at 4000 and up with lights on.

 

I think it's best to go and buy a small digital voltmeter and put it somewhere in the dashboard so I'd be able to watch the voltage when riding.

[AndyH]

 

I think it's best to go and buy a small digital voltmeter and put it somewhere in the dashboard so I'd be able to watch the voltage when riding.

Watch the road, it's more important.

 

;-)

 

Learned that one years ago when I had a crash during a similar testing session!

[Kiwi_Roy]

So, coming home from work still without a single flicker after charging the battery last evening, I went and connected my voltmeter to the battery terminals. Steady 12.75 when not running. Idle without lights was the same, but at times undulating between 12,5 and 12,9. Switching the lights on dipped the voltage appr. 0,2 Volts, undulation as well. Steady 13,9 V at 3000 rpm, 14,2 at 4000 and up with lights on.

 

You may wonder why the battery Voltage is higher with the engine running and lights ON

Its because the headlight current creates a Voltage drop between the battery and the point that the regulator is tied to (half way along under the tank). The regulator is set to control the Voltage at it's Black wire to the regulator case at 13.8 V

 

I have measured over 0.5 Volts drop as shown. So for the regulator to see 13.8 it has to pump 13.8 + 0.5 = 14.3 Volts into the battery. With the lights OFF you get zero Voltage drop so the regulator now sees the battery is too high and cuts back.

 

If you measure the Voltage drop as I show then remove and replace the 2 relays you will likely find it drops down a bit because in moving the relays you scrub the pins a bit to get a better contact.

 

IMHO it's this flaky voltage drop that causes the relays to cook themselves, they think the battery is too low and keep pumping current pulses until the diodes melt their leads off. Charge current vs Battery Voltage is some sort of exponential relationship.

 

Other Guzzis wire the headlight relay differently, just the coil goes through the start relay.

 

I can't explain the undulation you see but make sure the battery terminals and main ground are clean with some vaseline to stop oxidization. Please check your relay wiring, if the fuse feeding the headlight relay goes through the ignition switch like most other Guzzis there's a whole different can of worms.

 

[luhbo]

... Charge current vs Battery Voltage is some sort of exponential relationship...

Roy, better than 'sort of exponential' would be an example based on figures/calculations which will help to clarify how these things depend on each other.

 

Hubert