I thought I'd put together some information on a rectifier/regulator upgrade I did a few weeks ago on my Diversion. Hope some of you might find it useful.
The basic problem was that my bike seemed to be losing the charge in the battery. After a longish run it seemed necessary to stick the bike on charge every time just to keep the battery topped-up.
At first I suspected the battery: it was kinda ancient so was duly changed for a brand new one. The problem kept re-surfacing.
'Drain on the battery somewhere?', I thought.
Well, out with the multimeter again but there didn't seem to be anything significant. I even disconnected the heated grips by pulling the fuse out, just in case.
I looked at the charging system next. A look at this site proved useful:
http://www.triumphrat.net/speed-triple- ... grade.html
The divvy/seca has a typical three-phase supply to the rectifier/regulator. Looking at each of the windings on the alternator didn't show any unusual reading on the multimeter: no shorts or unusual resistances, the output also being the same on each winding when running.
The rectifier/regulator then...
BINGO!!
Looking at the resistances showed that one of the six diodes had shorted. When called on to stop the flow of current from that winding, when the voltage changed polarity, it failed, effectively allowing that phase to work against the other two. Result: reduced output to the battery, just enough to make the bike need battery volts to run.
Now what?
Mine was fitted with a stock Shindengen SH629A unit: a basic, cheap, do-the-job-and-nothing-else sort of thing. It's a basic SCR shunt style of regulator: excess energy is simply shunted back through the frame via the regulator, the unit runs hot and is not very reliable. Later secas/divvys came fitted with a slightly better unit, still a shunt type though.
The problem with a straight replacement is that it's no longer made by Shindengen. There are plenty around, with varying prices (!), but most seem to be cheap chinese copies. Might be okay for a wee while but...
https://www.shindengen.co.jp/product_e/ ... talog.html
Shindengen make a range of more efficient units that use MOSFETs. They run much cooler than stock and regulate the voltage better. I chose the FH 020AA kit from this place: much cheaper than from the UK, even with postage!
http://motoelectrixcom.myshopify.com/
Fitting was straight forward, except for the fact that new unit is much bigger than the old one. It can't go back in the original location , even if the bolt hole pitch is similar. However, slightly re-routing the existing wiring meant I could put it where the tool bag normally sits.
(NOTE: The original unit was earthed via one of the bolts to the frame: the replacement needs a separate earth wire run to the frame from the output connector.)
Extending the wiring from the alternator would be easy to do as well, allowing the unit to be mounted anywhere. The unit could also be wired direct to the battery if desired, however I chose to use the existing wiring and was pleased to see a steady 14.1 volts all the way through the rev-range.
(NOTE: The output takes a few seconds to ramp up to this once supplied with power from the alternator...)
The bike is now back to full health. As we say in Scotland: "Ya belturrrr!!!"
