Got a "tiny" charging problem...

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Rob Frankham
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Joined: Thu Aug 26, 2010 2:11 pm
Location: Scotland UK, 20 miles from civilisation up a dead end road!
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Re: Got a "tiny" charging problem...

Post by Rob Frankham »

In the first instance, you really do need to sort out why the charge lamp isn't lighting. The tests you have done suggest that the problem is in the wiring or conductors between the bulb and the voltage regulator/diode board (i.e. the blue wire) or between the bulb and the positive supply.

You don't say what happens with the other bulbs in the dashboard, the oil lamp, the neutral lamp etc... This will give you a valuable lead since, if these are working, you have battery voltage to the dash so the problem is either in the dash or in the blue wire. If they're not, then it's a rerasonable assumption that there is a problem with the 12 volt supply to the dash.

The 12 volt supply to the dash comes from the engine stop switch using a Green/Blue wire. This wire goes via a multiconnector under the tank. You can assume that the switch is getting power because the bike starts and runs (and the ignition system an the starter both use power taken from the switch branching off after the undertank multiconnector.

Conclusion:

1) There is either a break in the blue wire between the dash and the voltage regulator or
2) There is a problem with the multiconnector attached to the underside of the dash or
3) There is a problem with the copper tracks on the flexible printed circuit in the dash or
4) There is a break in the green/blue wire between the dash and the engine stop switch.

Get the light working as a first priority... if the bike still doesn't charge then you need to go on to the next fault... one thing is foir certain though, if the charge light isn't working, the bike won't charge...

Rob
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Kermit
Posts: 14
Joined: Sun Oct 19, 2025 8:26 am

Re: Got a "tiny" charging problem...

Post by Kermit »

gspd wrote: Mon Oct 20, 2025 3:20 pm Just a tip. As shown in your first pic, your brush tension spring is too 'loose'. You should wind it a full turn tighter. Remove the stator and check the inside one also.
Ok, got it. I will be trying to make these spring a bit "tighter". The front one might be easier than the back, as the latter's wire seems a little shorter, which already makes the brush to stick out less from its housing (compared to the front one).
1986 R65RT ex-French army, now getting some rest
2001 R1100S ex-CAT C, now properly kitted
2010 KTM 990 SMT ex-commuter, now questionable
2013 R1200RT ex-bargain, now money pit
Kermit
Posts: 14
Joined: Sun Oct 19, 2025 8:26 am

Re: Got a "tiny" charging problem...

Post by Kermit »

Rob Frankham wrote: Mon Oct 20, 2025 4:22 pm In the first instance, you really do need to sort out why the charge lamp isn't lighting. The tests you have done suggest that the problem is in the wiring or conductors between the bulb and the voltage regulator/diode board (i.e. the blue wire) or between the bulb and the positive supply.

You don't say what happens with the other bulbs in the dashboard, the oil lamp, the neutral lamp etc... This will give you a valuable lead since, if these are working, you have battery voltage to the dash so the problem is either in the dash or in the blue wire. If they're not, then it's a rerasonable assumption that there is a problem with the 12 volt supply to the dash.

The 12 volt supply to the dash comes from the engine stop switch using a Green/Blue wire. This wire goes via a multiconnector under the tank. You can assume that the switch is getting power because the bike starts and runs (and the ignition system an the starter both use power taken from the switch branching off after the undertank multiconnector.

Conclusion:

1) There is either a break in the blue wire between the dash and the voltage regulator or
2) There is a problem with the multiconnector attached to the underside of the dash or
3) There is a problem with the copper tracks on the flexible printed circuit in the dash or
4) There is a break in the green/blue wire between the dash and the engine stop switch.

Get the light working as a first priority... if the bike still doesn't charge then you need to go on to the next fault... one thing is foir certain though, if the charge light isn't working, the bike won't charge...

Rob
Hi rob,

You might have seen I've made a bit of progress regarding this issue.
I'm learning a lot on my bike with this kind of explanation though. Reading you, it makes a lot of sense. In front of a stranded motorcycle, that's another story. But again I'm learning.

Thanks for your input on the topic.
1986 R65RT ex-French army, now getting some rest
2001 R1100S ex-CAT C, now properly kitted
2010 KTM 990 SMT ex-commuter, now questionable
2013 R1200RT ex-bargain, now money pit
Rob Frankham
Posts: 1340
Joined: Thu Aug 26, 2010 2:11 pm
Location: Scotland UK, 20 miles from civilisation up a dead end road!
Contact:

Re: Got a "tiny" charging problem...

Post by Rob Frankham »

My apologies, read the first page and thought it was a new post.
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