No dash lights, then engine died

[Groover]

Hello, need some help - My G5 has been having intermittent charging issues, finally thought I had solved the issue with a new regulator - last night, the dash lights, head light and turn signals went out pretty quickly while riding, then by the time I realized that, the engine started to misfire then within less than a minute of all that, the bike just backfired and died. Dead battery, but also killed the engine electrics - where should I look? Is that a rotor issues?


Please advise - short week, didn't want to be bike stranded! This is on my 1981 G5, all OEM circuitry and OEM style parts.


Thank you in advance for the help.

[John Croucher]

Ignition switch corrosion is my first place to look.  Checking voltage can be misleading.  You can get a voltage reading, but due to massive corrosion in the ignition switch, you are not getting any amperage current.  I chased multiple problems on my Quota rebuild.  When i pulled the ignition switch apart and cleaned the green out of it, the bike ran better and the lights were brighter.   

[Groover]

Thank you John, will check that a little later, though I did just replace that earlier this year. The symptoms of that were a little different, that, when it acted up it was basically a crisp on-off, this was just an abrupt horrible performance (I was at a stop light) acted a bit as if were going into reserve (not the case) I upped the throttle to keep it running, and just got worst until it just backfired and died - dash was also very dim, almost out but not all out, turn signals did not work either during that time which was a total of maybe 1-2 minutes.

[blackcat]

I chased a charging problem for a long time and it turned out to be a hairline crack in the brush holder, the brush weren't getting good contact to the rotor.  And a few years later there was the twisted rotor problem, basically the claws on the rotor twisted:

https://wildguzzi.com/forum/index.php?topic=102768.90

[Groover]

mangled brushes and/or rotors would cause engine running issues, correct?

[Antietam Classic Cycle]

Unplug all of the Molex connectors from the back of the headlight, clean with Caig DeoxIT and plug back in. Might not help, can't hurt.

[Groover]

Will take a look at that as well, did that a month or so ago as it had unplugged, cleaned and snapped it back in, may have come loose again. Not sure - what are the symptoms (to the engine) when a rotor or brushes go bad?

[blackcat]

Will take a look at that as well, did that a month or so ago as it had unplugged, cleaned and snapped it back in, may have come loose again. Not sure - what are the symptoms (to the engine) when a rotor or brushes go bad?

I zip tie the Molex connectors together to avoid that problem. There are no motor symptoms when either the rotor or brushes are bad.

[John A]

Check the wiring under the fender to the tail light. It sometimes shorts out because of its living conditions. I’d suspect the rotor as well, they can develop a flying short when the centrifugal force makes it short out when running.

[Groover]

Thanks again for the replies, Went home, bike started right up (vs dead when I parked it) dash lights worked and so did the turn signals, so that doesn't help. I took the rotor cover off (just our of curiosity, thank you for clarifying John A), all looked good, checked the Molex connectors at the headlight, all was snapped in and tight, disconnected and reconnected them still and all was nicely lubed from a few months ago (with ACF-50), switch is new so hoping it's good, seems to be, I did tug on the cable to the taillight and turn signals in the back, nothing visible that looked like could short-out, but did move them a little from there current resting spots - will check more closely after work, but at a glance, all looks protected (no rubbed out wiring) - thanks again - need to build some trust with this beast again, got stranded, luckily just 1.2 miles from my house, wife with me, we pushed it slightly up-hill in the dark, so the word Vintage bike is a little taboo at the moment in my house   

[blackcat]

Deferring to John's point about the switch, have you replaced the original switch? The reason I ask is because I'm always suspicious when a bike fixes itself with no input from something I did to the bike.

[Groover]

I replaced the switch with a new one not too long ago (a few months maybe), maybe it failed, not sure - I'll definitely take a better look. I agree, not particularly at ease with it all of a sudden working...

[blackcat]

I can’t imagine it would fail so quickly but you might have a loose connection.

[Groover]

Ordered a replacement switch just in case to have on hand with the holiday weekend coming up. I'll check everything thoroughly again, thanks again everyone for the help. At least I know now it's now the rotor, though still not totally confident on the charging issue - looking at these as two as different issues. I did replace the battery this year as well as the regulator - have not checked the diode board yet.


I can deal with the battery not charging, I bought a jump starter to carry with me when going out of town, the dying out while backfiring was new to me. Totally unexpected.

[Groover]

Thanks again for the help, and hope everyone is have a safe Memorial Day weekend.


On this, the bikes seems to be running, no engine issues. I did go over all the connections, things looks really good. I spread and cleaned the molex ones at the headlight, all snaps in tightly. Checked the charge light bulb, it's not lighting up at idle (it has in the past), but the bulb and connectors are good.


At this stage, I have new battery, new rectifier (I do have a new ignition switch now on hand, but that would be for the running issue and I'm good on that I think), but for the charging, could the rectifier/diode board be the issue? I have a spare in my storage unit, will likely try it tomorrow.


Bike runs, rode it a few hours yesterday, though not charging. I have a NextPow jump starter strapped to the bikes rack, and will likely be using it by end of day, lol.


So next in line is the replacing the rectifier. What else it could be. Wiring is good

[MattP]

stator

[Groover]

 Which should I try to replace first. I have that as well.l

[Groover]

Just checked voltage, reads 18.01 volts after battery change over night on battery tender, which seems high, anyway, giving it throttle doesn't change the ready, so apparently not charging, but could that be because the regular is set to 14 (something) volts? It's one of the duralast (I think name of brand) anyway, just an update and had a meter on hand.,

[80CX100]

My CX100 had the same symptoms a few years ago,,, bike ran fine,,,but no charging,,,had to recharge the battery at home & ran it for quite a while as a total loss system.

Later discovered,that the sensor signal wire to the R/R, had become disconnected;,,, no signal,,no charge;,,, fixed by simply reconnecting the wire.

If as you say,the wiring & connections are good, maybe there is a diode or similar on the same path,burnt out inside the R/R.

Fwiw idk

Good luck

[blackcat]

Rotor. Did you check ring continuity?

[John A]

https://www.euromotoelectrics.com/default.asp
I thought these guys had a trouble shooting guide but I don’t see it now.
As you probly know the lite has to work for it to charge. Did you ohm the slip rings? Is there 12 v to the DF terminal on the stator?

[n3303j]

mangled brushes and/or rotors would cause engine running issues, correct?

Disconnected brushes or a failed rotor (on my T3) show no visible symptoms whatsoever.  You just run until the battery is empty. Then you know. CHARGE failure light goes on through rotor and brush continuity. Loose that and you don't get the red light at key ON. AND you don't get a red light indicating you are discharging as you ride.

Wore a brush short and it hung on the pigtail wire in the holder. Dead Odyssey was the indicator. Thank goodness it failed top of a long hill.

Another time couldn't restart after fuel up. Overnight charge at a sympathetic neighbor's and I made it home on the same Odyssey's box of sparks. The rotor had gone OPEN  circuit.

One time I did have a ground cable loosen up at the chassis and the intermittent symptoms were about to make me nuts. Finally spotted the loose connection and all was well.

Once a year I spin the fuses in their holders and spray them with ACF-50. Used to die while riding every two or so years. Spinning the fuse reestablished sufficient contact to continue the journey. Now the annual "oil and spin the fuses" is on the maintenance schedule.

[John A]

+1 on spinning the fuses to clean them , especially the VW type 

[Groover]

Thanks again, update, just cleaned and ACF50'd the fuses, same. Will keep updating this post with the fix. Haven't had a chance to replace the other parts. Thanks again.

[guzzisteve]

https://guzzitek.org/gb/ma_us_uk/1000/1000SP_G5_Atelier(GB).pdf

Page 127 says how to test.

[PeteS]

These still have a diode board? Thats the first place I would look. Make sure all the spade lugs are tight and don’t have signs  of overheating from poor connections.

Pete

[Antietam Classic Cycle]

ACF50 would not be my choice for electrical connections. Caig DeoxIT would.

[n3303j]

ACF50 would not be my choice for electrical connections. Caig DeoxIT would.

DeoxIT is a cleaner as far as I can tell.
ACF-50 is a preservative and lubricant.

So DeoxIT to clean the stuff up.
Then ACF-50 to keep it from re-oxidizing and keep it lubricated.
Spray that stuff liberally into all handlebar switches and they work and last forever. Fill the connectors and they stay connected. FAA approved for all aircraft electronics as it will not damage any non metallic parts. Super penetrant. So it gets to all associated parts of the switches.

I put that s#it on everything!

[Groover]

Did the test posted and quoted by ohiorider in this thread, and it's definitely the rotor. I'll be replacing that hopefully later today (weather dependent, no garage)


https://wildguzzi.com/forum/index.php?topic=78054.0


I'll follow up with the "for sure" once it's all set and done, but looks like the rotor is it.


Thanks again.

[chuck peterson]

Wild a$$ guessing..

Try measuring the rotor brushes…..release the spring and pull them out..lower limit is in the service book I believe

Mine wore down enough to not be close enough..

But they looked like they were fine

The wire hung up on the holder ..

and the brushes were the tiniest distance away from making contact ..they ‘looked and felt fine’

Describes your no red light condition w the key on