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Charing ridle

395 Views 2 Replies 2 Participants Last post by  dr_gallup
Hi All,

I'm working on a friends bike, a Triumph Speed Triple 1050 and it is having some weird charging issues. But before you tend to give the regular answers on regulator/alternator issues bear with me :

So I started my regular way of checking (as I have fixed many other charging issues on different bikes before, I tend to think that I know what I'm doing ;) ) :

  • test the battery. : good (as expected, as my friend already replaced it for a new one and it is charged)
  • start the bike, voltage is around 12,5 at the battery so no charging (at any rpm )
  • disconnected the alternator and checked output voltage of the aternator at 5.000rpm . Nice 70 volt ... so that's perfect.
  • connected the alternator again, disconnected the output end of the regulator and checked output voltage : 14,5 v

Now I'm confused. Triple checked everything, but it is what it is.

Reconnected everything and still no charging at the battery end.

Created the 'mosfet' workaround and connected positive and negative output from the regulator directly to the battery, but still it reads 12,5 v at any rpm
Took another battery just to be sure, and now around 12,9 volt, but still no charging
Removed the output connector from the wiring, so only the direct connection to the battery is in place, and still only 12,5 v
Removed the output wires at the battery end (so regulator output is not connected to the wiring of the bike), and measured directly to them and 14,5 v output.
Connected the output connector and left the 'mosfet' wires loose and still only 12,5 v.....

So, as soon as the output of the regulator is connected to the bikes wiring, the regulator fails. Even with another regulator this issue is the same....

Checked fuses and all are good (unless I'm missing a fuse box somewhere other than the one under the seat in front of the battery). Switched relais to see if that would make any difference, but no difference. But no luck so far.

As always with electrical issues, the solutioin is probably really simple, but finding it.........

I'm just leaving the charger on the bike for now, and give it a good night sleep. And hopefully somebody here as a bright idea of where/what to look.....
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After a few good nights sleep I turned back to the issue.

Now in the past few years I have started skipping some test because they were inconclusive every single time.... and that was my mistake.... Turned out the alternator wires were grounded and hence the alternator worked well (70V output) and at the regulator end you measure 14+ volt without issues. But when you connect the regulator to the wiring loom it shortens out.....

After replacing the alternernator all is well again......

Note to myself: never ever skip a simple test again......
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