Question about 2008 Triumph Triumph Bonneville

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Bonneville charging system troubles

Hello finally joined up here, great info by your members and hope to contribute to this great resource. ok heres the problem; the motor is a T120c its a 63 or 64 (not a preunit) my battery is brand new and water is fine, i have rewired the whole bike and silver soldered and heat-shrinked all connections. how do i test the alternator? i have a multimeter, the battery when charged is 12.5vdc when running at high idle it reads 8.6vdc i am assuming the drop is from the draw of the bike running with no charge comming in... where do i start? it has tympanium and boyer electronics. these are both zip tied together underneath the gas tank, between the frames. is this a bad place for them? im also wondering if the tympanium is faulty. if i had some test procedures like resistance values or something i could figure this out. the headlight doesnt go dim to warn me that the battery is going, it just cuts out and thats it, kapoot.

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Check your Zener Diode, it might be shorted causing a charging dump to ground. I don't have typaniumtroubleshooting guide handy, sorry

Posted on Nov 10, 2008

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