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Discussion Starter #1
Last winter I ended up having to jump start the Speedmaster a few times, had the battery tested and sure enough it had reached the end of its life so bought a new one.
Came out this morning to set off to work to find that the battery was dead and once again had to resort to a jump start. It wasn't that cold last night but the bike did have to endure one hell of a downpour on the way home. Any ideas?


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Once you have it started, check your voltage to be sure your generating system is working properly. You should have ~ 14V - if below 13 then you definitely have either failed R/R or stator. If voltage is good when running, it would point to battery again.
But you didn't just leave in Park, perhaps? :p
Any accessories on the bike?
 

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Discussion Starter #3
Thanks, will have a check on the voltage. The only thing extra on the bike which could have an effect is the alarm, but that's on every night so if it were that causing the problem surely the battery would be dead every morning?


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Try to fully charged your battery by external charger and disconnect your alarm, to see if the low battery condition comes back again.

It appears that your charging system is marginal or something is draining your battery.

Good Luck.
 

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I removed my alarm...ended up causing other electrical probs and immobilising me, the thing was a pain in the ar*e.
 

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Was it a factory installed alarm? It must function more than just an alarm but with a disabling device.

You may have to check the schematic diagram to sort thing out. Yeah, it sounds a pain in the azz. :)

For the OP's problem, using an accurate volt meter even w/o disabling the alarm, one can monitor how much voltage drops over a period of time. A healthy system, the battery should have sufficient juice to start the engine within 2 weeks of non running.
 

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On the subject of removing alarms, if it is a factory alarm, there is a block with some jumper wires that must replace where the alarm plugs into the harness. Some aftermarket alarms will have a disabling feature which causes an open circuit on what ever wire it's installed to.

To the OP, I had poor charging when I first bought my America. Spent a lot of time chasing it down to include checking full continuity of the harness and condition of the connectors. I bought a new reg/rec only to still had very weak charging. I then rewired the original reg/rec, bipassing the factory harness, and that did the trick. Maybe one of the connectors had a half-bad crimp underneath or something, who knows.

Anyway, based on that experience I say if the voltage at the battery doesn't look promising, check the stator's AC output. If that checks out, then try cleaning all the contacts in the charging circuit and reassembling with dielectric grease. If the voltage at the battery is still questionable, then consider a rewire or a reg/rec upgrade along with a rewire. An extra wire will have to be run in order to maintain the carb heaters if desired.

Here's DEcosse's excellent run down:
http://www.triumphrat.net/speed-tri...-diagnostics-rectifier-regulator-upgrade.html

And here's the slightly odd voltage behavior I see with the rewired stock reg/rec. Been working just fine like this for quite some time though.
 

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Discussion Starter #9
Thanks guys, lots to think about. Mechanical processes have always made sense to me (one thing moves which causes the next thing to move etc) but electrics, I'll freely admit, have always been a bit if a mystery to me. Looks like it's time to dig out the Haynes manual and teach this old dog some new tricks!


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... And here's the slightly odd voltage behavior I see with the rewired stock reg/rec.
That is quite typical of OEM SCR R/R:
When at idle, the SCR's are completely off and so there is no shunt at all; when the rpm increases, the SCR's start to conduct - the ability to regulate is not precision with this type of system and invariably the output voltage indeed drops slightly as the rpm increases.
 

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Cool, thanks for the explanation! I had been wondering, but not enough to actually look into why it acted like that. I'd also had way more than my fill of charging systems reading and was perfectly happy to just have things running reliably;)
 
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