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Intermittent charging light Thu Aug 05, 2021 8:34 am
tinyspuds
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Yesterday alternator stopped charging.
Battery is 13.1v at rest, drops to around 12.9 with key on, starts fine atm.
On a 170 mile run yesterday voltmeter started showing around 11.8 at highway speeds. Got home and battery showed 12.4 at rest.
This morning I cleaned and tightened the alternator red and blue connections. Removed regulator: brushes clean and practically as-new length with free movement.
9 times out of 10 the battery charge light isn’t lit at key on (this is a new thing today).
If it is lit it goes out when starter pressed never to return. When its on its the usual nice and bright.
Voltage measured at both battery terminal and at alternator terminal - no change across the range - tickover to 3k.
I suspect a faulty charge globe or connection, any more impressive thoughts?
Is there a way to simulate the exciter circuit (3 ohm bulb +ive connect to the alternator blue and earth to engine?) so I can rule confirm its not an alternator issue.
I have a working 30A alt I could I could swap in but would prefer to do EITHER that job or the lunch box dismantle. Where would you guys put your money?
That said, all my plans for Biaritz and Monte Carlo have been cancelled for this season so I could do both jobs if required. Then maybe Ill get round to doing the LED lunchbox backlights Ive been thinking of.
TIA, Stu.
Last edited by tinyspuds on Thu Aug 05, 2021 8:36 am; edited 1 time in total (Reason for editing : clarity)
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1985 BMW K100RT + Hedingham HUB and LL’s. VIN 0028106.
1986 K100RS in boxes. VIN 0141918.
1954 Royal Enfield 350 Bullet. Original.
2000 Hayabusa with Charnwood chair, Wasp forks and EZS wheels.