Charge light comes on under heavy acceleration (850T3)

[ksd124]

Hello,

Has anyone experienced their charge light coming on under hard(er) acceleration and if so, any clues on the cause?  It seems the harder I accelerate, the brighter the light comes on.

Cheers for any help you are able to give.
Kelvin

[rodekyll]

The T3 has the bosch alternator.  It has brushes.  The brushes can bounce with vibration.  One trick with those is to install the stator with the brushes at the 10:00-ish position.  It may be an urban myth, but many have reported the bounce to be minimized by repositioning the stator and cleaning the slip rings.

Another common problem causing this is a bad regulator.

[jabberwocky]

I once had some similar problems with my R100, which has the same charging system as the T3. I don't remember exactly when it did what, but the charge light would come on at certain speeds and throttle positions. Usually backing out of the throttle would make the light go out. Upon inspection, I would find that the brushes would be all chipped up at their contact faces, so I'd replace them, but the problem would come back, and again the brushes would be chipped up. I couldn't see anything wrong with the slip rings, or the brush holder, but not knowing what else to do, I swapped in another brush holder that a friend gave me. That was about 15 years ago, and I've never had the problem again. It was a relief to fix it, but I never could discern what was wrong with the old brush holder. I can send you a brush holder if you would like to try it out.

[Kiwi_Roy]

I think its the warp drive cutting in ;D
The electricity can't keep up with the bike.






Seriously since the rotor is fixed to the crankshaft could it be the shaft flogging around under certain conditions leading to brush bounce?

[Mike Harper]

The T3 has the bosch alternator.  It has brushes.  The brushes can bounce with vibration.  One trick with those is to install the stator with the brushes at the 10:00-ish position.  It may be an urban myth, but many have reported the bounce to be minimized by repositioning the stator and cleaning the slip rings.

Another common problem causing this is a bad regulator.

OR----  The brush springs were probably reinstalled wrong and are one turn looser than called for..  The brushes belong at the top. ;D

[pressureangle]

Possible, but less likely, is that your system is marginal (very likely) and your ignition consumes enough extra battery at higher RPMs that it puts you over the edge. I have a Dyna ignition in mine, and the battery rarely ever got charged-the headlight and ignition took more than the alt. could supply unless extended higher RPM time was spent. I sucked it up and went for the Saprisa conversion and never had another issue.

[ksd124]

Thanks everyone - a number of things to have a look at.  I've not done any fault finding as yet, but will report back when I do (assuming I'm able to resolve it). Cheers, Kelvin.


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[ksd124]

Just for reference, whilst I don’t know specifically what wire or earth was creating the problem, I gave the charge system a bit of a going over - fixing a number of connection points and earth points.  Problem has gone.  Seems the charge light goes off at lower revs also.  A proper test tomorrow when I cover a few hundred kms.  Thanks again, Kelvin.