Another alternator problem

[higgy]

Hi from across the pond,

After riding my 1980z for about 3 or 4 miles the volt meter started to drop from 12 to 11 to 10 and so on, I had the stator checked and was found to be faulty so I had it rewound and fitted a new regulator. After all this it was great pushing out a good 13 volts, after 2 road tests of about 20 and then 40 miles the volts started to drop again, it seems now if I start it up its between 12 /13 volts then drops to 11.6 if I stop it and restart it goes back to 12/13 volts also the meter fluctuates when on the lower volts. What do you think?

[dan1995]

did you check the brushes, or how about the condition of the a and b plates and the spring tension also are you using a good volt meter or the meter on the bike. the one on my 82 reads high all the time , however if checks out fine with my multimeter

[Chris]

Hi from across the pond,

After riding my 1980z for about 3 or 4 miles the volt meter started to drop from 12 to 11 to 10 and so on, I had the stator checked and was found to be faulty so I had it rewound and fitted a new regulator. After all this it was great pushing out a good 13 volts, after 2 road tests of about 20 and then 40 miles the volts started to drop again, it seems now if I start it up its between 12 /13 volts then drops to 11.6 if I stop it and restart it goes back to 12/13 volts also the meter fluctuates when on the lower volts. What do you think?

Higgy,



As you probably already know, there are a number of things that can be causing your low charge problem. Some would be...........

Battery condition

Generator brush condition

Corroded plug connectors



Last but not least........

clutch condition Make sure your clutch isn't slipping and has no missing spacers.



Hope some of this helps.



Chris



P.S.

Its a small world. Made my second visit to Southhampton last year.

[EMS]

Chris is right. There are many possible reasons for malfunction. One of the most overlooked one are the connectors. Especially if the condition gets worse as the bike runs longer it may point there. The corroded connections in the plug cause a higher resistance, which in turn causes temperature to go up which in turn causes higher resistance...a vicious circle, which will eventually cause the plastic plugs to melt. Make sure you pull the plug from the alternator off the connector to the regulator (located under the right side cover) and clean all connections thoroughly

[Jeff Bennetts]

If the connectors are dirty they will feel warm to the touch and you'll notice some warping of the wire covering, also when you clean them the best way is to remove the pins with a dental pick so you can clean the corrision at the pin and wire connection where its crimped to the pin.



jb

[higgy]

Thanks for all your help, can anyone tell me if the alternator is switched on and off by the regulator because I have taken it out of the bike, left it pluged in and drove it with a electric drill. When the alternator got hot it stopped charging, I tryed it on my old CB750 with the same results. I have replaced the stator and the brushes, could this be a rotor fault.



Matt aka Higgy

[alimey4u2]

higgy, I would humbly suggest that the alternator stopped charging when the battery became fully charged ?? Heat would be generated in the testing procedure, how much, I don't know......

Measure the resistance of your rotor ( track to track,) as it can be critical.....

[higgy]

Thats what I thought , but if you then crank engine over running the battery down you would think the alternator would start charging again, but it doesn't until it has cooled down.



Higgy

[alimey4u2]

The component most effected by heat would be the low resistance item & that would be the rotor. However, I really think you need to investigate this source of heat.... IE bearings ???



Has any other board members noticed overheating in alternators ??

[EMS]

Thanks for all your help, can anyone tell me if the alternator is switched on and off by the regulator because I have taken it out of the bike, left it pluged in and drove it with a electric drill. When the alternator got hot it stopped charging, I tryed it on my old CB750 with the same results. I have replaced the stator and the brushes, could this be a rotor fault.



Matt aka Higgy

When you did this, did you monitor the charging condition with the Voltmeter on the bike orr did you connect a separate instrument? I am trying to understand what you mean by the "alternator..stopped charging"

[dan1995]

as ems said i wouldn't trust the factory gauge as i said earlier the one on my 82 read about 1.5 volts higher than real voltage hook up a good multimeter and check it while riding

[FalldownPhil]

Larry,

In answer to your question. YES, right before the bearings seized.

Best,

Phil

[alimey4u2]

Thanks Phil, I thought that may be an issue.........