Electrical problems - one for the experts

[dark_bike]

Now that it gets colder I've noticed a new problem with the electrical system. It seems that the battery isnt charged sufficiently during my ride to work and back. When it is really cold the battery simply is too weak by the end of the week to start the engine, even though it is only a year old.

I've had this problem before on a Guzzi, on a 750 Targa to be precise, and I later learned the the generator on these bikes was rather undersized.

Another problem that still persist is the fluctuating brightness of the lights, both headlight and instrument lights. A couple of times they become unusually (to me at least) bright then dim down again, untill they settle, like there is some sort of voltage surge. Doesnt affect the engine though.

last but not least the indicators blink faster at really high speeds/revs (say 100 mph/6000 revs or so)

I checked all earth connections I could find and they seem all right.

So the big question now is: what could that be?

To me it would seem that there is something wrong with the voltage regulator but what do I know...?

 

best regards

Tom

[guzzimeister]

Now that it gets colder I've noticed a new problem with the electrical system. It seems that the battery isnt charged sufficiently during my ride to work and back. When it is really cold the battery simply is too weak by the end of the week to start the engine, even though it is only a year old.

I've had this problem before on a Guzzi, on a 750 Targa to be precise, and I later learned the the generator on these bikes was rather undersized.

Another problem that still persist is the fluctuating brightness of the lights, both headlight and instrument lights. A couple of times they become unusually (to me at least) bright then dim down again, untill they settle, like there is some sort of voltage surge. Doesnt affect the engine though.

last but not least the indicators blink faster at really high speeds/revs (say 100 mph/6000 revs or so)

I checked all earth connections I could find and they seem all right.

So the big question now is: what could that be?

To me it would seem that there is something wrong with the voltage regulator but what do I know...?

 

best regards

Tom

 

Hi Tom

 

almost certainly the regulator. Two checks you can do. You will see two yellow wires from the alternator which plug via bullet connectors to the loom. Get a multimeter, set it on a range which will handle 600v AC, and with the engine at idle check the voltage. It will start off quite low but by 1500 rpm or so it should be showing up to 600v, certainly 100s of volts. This will tell you if yoiu have an alternator issue.

 

Next, plug the alternator back into the loom and using 20v DC on your multimeter, check the voltage at the battery. As engine revs rise you should be seeing 13.5 - 14.2 ish volts, and the voltage should rise gently with engine revs. Anything less than 13.5v suggest regulator is iffy.

 

Finally if both these check out OK, start the bike and put the headlights on. If the lights get significantly brighter as you blip the throttle, you might have a failing battery, ie it's taking charge but not keeping it.

 

A sure sign of charging problems on V11s it that when volts get low, say 8.5v, the tacho stops working. If you see this happening on your bike, don't assume it's a dud tacho, ride home asap and check the above.

 

Hope this helps

 

Cheers

 

Guzz

[fotoguzzi]

Does your regulator get ground thru the mount to frame? might not be the problem but I run a wire from the reg body straight to the neg battery post. that way your not relying on a possibly dodgy ground connection.

[felix42o]

Also, the connectors on the mentioned yellow wires coming from the alternator are not of super high quality...check them for corrosion and tightness, and the condition of the bolts/threads that mount the regulator/rectifier to the frame of the bike. This causes alot these problems.

[luhbo]

Is the battery or the rubber below it wet? If so, how does the fluid taste?

 

hubert

[Kiwi_Roy]

Guzzimeister and Photoguzzi are right on.

I have pulled 3 regulators apart, each one had a bad connection to one of the diodes. The good thing is it's very easy to check the diodes because the wire directly between each yellow wire and the red wire. See the attached sketch.

 

Photoguzzi pointed out that the regulator ground can be a problem, relying on those captive screw spring clips "dodgy ground connection." His solution of running a wire back to the negative is a good one, I drilled a hole through one of the reg fins and ran a fat wire from there to a timing case bolt. Don't forget to put some grease on the aluminum to copper connections to prevent corrosion.

 

I have a theory that the regulators are damaged because of a bad ground to the case connection. The regulator tries to compensate for the lost voltage (it sets the voltage between black wire and it's case not across the battery)

If the connection to the case is bad the regulator still maintains it's setpoint of 13.8-14 Volts between red/black wire to case so whatever voltage is lost between the case and ground is added to the battery. As it tries to push the battery voltage over 14 Volts the current goes sky high until it melts the leads off one of the diodes, after that you limp along on just half the charging.

 

Heres the basic circuit, notice how all the current to the battery has to pass back through the "dodgy ground connection" and back to the alternator. The Voltage reference is the black wire of the black/white pair.

 

 

Note: The voltage reference the regulator uses is the Red/Black wire that also supplies the idiot lights and tacho via the headlight relay. If you unplug the headlight relay the charging will stop.

 

Something else to check is the 30 Amp fuse, see if it's getting warm or is welded in, a sure sign of a bad connection there.

Connect your digital meter to the battery and strap it to the tank so you can check the voltage while riding.

[Skeeve]

I have a theory that the regulators are damaged because of a bad ground to the case connection.

 

Glad you brought that up: I was going to mention something about that too. Honda had a serious problem w/ early GoldWings eating their stators; it was eventually traced to the molex connector under the left sidecover experiencing corrosion at the connector and gradually increasing resistance until the current the regulator was demanding to compensate eventually blew up the stator [which, since it is inside the cases on the back of the engine, was a very expen$ive repair!] The solution, per one of Honda's service bulletins? Cut out the molex connector & solder the wires together! Since the motor on a G'wing comes out of the frame so rarely, it's easier just to cut & resolder the wires in the event of that rare occurrence...

 

NB: does this mean that HMC gets a bodge point?

 

So I am of the mind that improving the connection to ground for the VR on the Guzzi is of immediate importance [isn't it interesting to note how many of the myriad niggles on V11s seem to relate to their electrics? ]

[Kiwi_Roy]

 

I was going to mention something about that too. Honda had a serious problem w/ early GoldWings eating their stators; it was eventually traced to the molex connector under the left sidecover experiencing corrosion at the connector and gradually increasing resistance until the current the regulator was demanding to compensate eventually blew up the stator [which, since it is inside the

 

Skeeve, Glad you bought up the Goldwing, I picked one of those up a couple of months ago, an 83 with 305 original km on the clock, it sat in a garage for 27 years. I will certainly deal with the connector as you suggest.

Update: I chopped the Molex connector out and soldered the wires with some heat shrink. The pickup wires for the ignition also have a connector right there, I just slathered that in grease.

 

Here's a picture of the two diodes inside the Ducati regulator the one at the top has melted the lead off and you can see the arcing.

Cheers

Roy

[dark_bike]

Thanks for all the advice guys, gives me something to do tomorrow :-)

 

I'll let you know how I get on.

 

Tom

[luhbo]

Don't forget to look whether the battery was sweating or not.

 

Hubert

[Skeeve]

 

Skeeve, Glad you bought up the Goldwing, I picked one of those up a couple of months ago, an 83 with 305 original km on the clock, it sat in a garage for 27 years.

 

OMG! How did that happen? Are you certain the P.O. didn't just turn the odometer around [iIRC, they only go to 99,999 before rolling over...]

 

305 original km is buying it at one of the few & far between dealerships back in '83 and riding it home!

 

Does your '83 have the comstar [pressed & riveted steel, '81 to early '83 model year] or the cast alloy [late '83 on] rims? I hope you lucked out & got the cast wheels, because even tho' they're heavier, they're hold up better under high mileage; the comstars reportedly would "get loose" over time.

[Kiwi_Roy]

OMG! How did that happen? Are you certain the P.O. didn't just turn the odometer around [iIRC, they only go to 99,999 before rolling over...]

No, I'm sure it's genuine Note the plate sticker expired early 84.

Everything is still tight, propstand etc, the original paint is immaculate but the brightwork suffered.

Brakes were all gummed up, I had to drill the muck out of some of the carb passages.

So the story goes old guy's wife talked him into buying it and the rode to the beach where they laid it down and couldn't pick it up, took it home and parked it.

Alloy wheels.

I'll never get it back to perfect but it should be a great bike to take my wife along.

Roy

[raz]

So the story goes old guy's wife talked him into buying it and the rode to the beach where they laid it down and couldn't pick it up, took it home and parked it.

 

 

A relative of mine has a GW. I recently tried just raising it from sidestand on non-level ground (so it had some extra angle). Man, that was heavy. I haven't had the guts to ride it yet. I'm sure it's OK as long as you just ride it ahead but any maneuvering in awkward situations would be tough for a guy like me: I'm just 70 kg...

[dark_bike]

Now that it gets colder I've noticed a new problem with the electrical system. It seems that the battery isnt charged sufficiently during my ride to work and back. When it is really cold the battery simply is too weak by the end of the week to start the engine, even though it is only a year old.

I've had this problem before on a Guzzi, on a 750 Targa to be precise, and I later learned the the generator on these bikes was rather undersized.

Another problem that still persist is the fluctuating brightness of the lights, both headlight and instrument lights. A couple of times they become unusually (to me at least) bright then dim down again, untill they settle, like there is some sort of voltage surge. Doesnt affect the engine though.

last but not least the indicators blink faster at really high speeds/revs (say 100 mph/6000 revs or so)

I checked all earth connections I could find and they seem all right.

So the big question now is: what could that be?

To me it would seem that there is something wrong with the voltage regulator but what do I know...?

 

best regards

Tom

 

Hi Tom

 

almost certainly the regulator. Two checks you can do. You will see two yellow wires from the alternator which plug via bullet connectors to the loom. Get a multimeter, set it on a range which will handle 600v AC, and with the engine at idle check the voltage. It will start off quite low but by 1500 rpm or so it should be showing up to 600v, certainly 100s of volts. This will tell you if yoiu have an alternator issue.

 

Next, plug the alternator back into the loom and using 20v DC on your multimeter, check the voltage at the battery. As engine revs rise you should be seeing 13.5 - 14.2 ish volts, and the voltage should rise gently with engine revs. Anything less than 13.5v suggest regulator is iffy.

 

Finally if both these check out OK, start the bike and put the headlights on. If the lights get significantly brighter as you blip the throttle, you might have a failing battery, ie it's taking charge but not keeping it.

 

A sure sign of charging problems on V11s it that when volts get low, say 8.5v, the tacho stops working. If you see this happening on your bike, don't assume it's a dud tacho, ride home asap and check the above.

 

Hope this helps

 

Cheers

 

Guzz

 

Hi Guzz,

 

didnt have the time to sort things out fully, but did manage to measure the charging voltage at the battery with the engine running. With a bit of revving that was 14.0 volt, so that would seem OK.

Next, I'll clean the regulator mountings to make sure it does make a good ground.

I've got to improvise a bit with workspace at the moment (too many vehicles, too little space) so anything involving taking fairing parts off will have to wait a bit.Cant get at the connector of the alternator to the loom very well right now.

 

cheers

tom

[Skeeve]

A relative of mine has a GW. I recently tried just raising it from sidestand on non-level ground (so it had some extra angle). Man, that was heavy. I haven't had the guts to ride it yet.

 

Well, they're a bit overwhelming at first, like you said: once you tip it beyond a certain point from vertical [say, 15deg either way], you begin to realize just how MASSIVE they are. The thing is, they've got such low c.g. that as long as you're careful, they don't have a tendency to reveal just how heavy they are [unlike some of the modern sport tourers like the FJ1300, ST11/1300 or Connie 14, which have high c.g's that will bite you if you're caught unaware...]

 

I'm sure it's OK as long as you just ride it ahead but any maneuvering in awkward situations would be tough for a guy like me: I'm just 70 kg...

 

As you say, as long as you're underway, they're not bad at all. The "parking-lot paddle maneuvers" are why Mother Honda added the electric reverse gear on the GL1500, which was even more massive than my GL12 [the last of the F4s.] NB: my understanding is the reverse works by running the starter motor backward in gear, possibly w/ a compression release as well? A similar setup could conceivably be retrofit/achieved by a gifted amateur, but I'm a big enough guy[1] that I'm just not interested in going there...

 

 

 

[1] - Mountain bike racing "Clydesdale" class, 200+ pds - or as I like to say: "Normal size, not a midget like most everyone else..."