Well, I rode the bike to work today.  (All of a mile and a half - the long way! )  Maybe I'll take 'er for a spin up the canyon on the way home ... it feels like everything needs a good "blowing out".

Note to self:  Reattach your Digital 5 Function Volt Meter for the next week or two ... 

[Click for larger image]

My regulator is blown too. 

I made some measurings and followed Clymer instructions to check the regulator, but there are some words really important there:
They make a warning: "These measurings must be taken with the Suzuki Test Tool #xxx, otherwise may be wrong".

As the regulator is not a resistive device, (it is a semiconductor), resistance readings will depend on the tester used, since each tester will send a signal (different from others) through its wires to check the resistance.
But a semiconductor will behave different from a resistance, so resistive readings on semiconductors is not a good thing.

I tested my blown regulator with several testers, and all the gave different readings.

On the other side, it looks like you are worried about your alternator giving "only" 65V. In my opinion, this should be no problem: the regulator will eat all the voltage that the alternator supplies beyond 14.2V, so if your alternator is a but "low", your regulator will be less stressed. If the regulator were constructed in another way (switching regulator, or DC_to_DC converter, or any other flavour of these technologies), a low input might lead to a defective output; but the "classic" regulator in automotive applications is only a "power eater" that will convert all your overflowing current to heat.


I've ordered a new R/R on ebay. While it reachs home, I use the bike recharging the battery each night. Using only the parking lights, I can get about 20miles of use with no problems.

Thanks for the reminder, Marc!

I ended up with a boatload of data, and I wasn't sure how to best relay it in the "How-To" I created in the FAQ forum.  But the R/R part of the "How-To" is certainly INaccurate as it stands, so I'd better do something before anyone else gets tripped up.

BTW, if you have a "Diode Test" function on your meter, the [Fault Finding Flow Chart For Motorcycle Charging Systems] by ElectroSport Industries contains procedures that matched the readings on my (good) R/R unit.  Start at the top of page 3 in the PDF.  (I also need to add an "optimized" version of the flow chart, created by our own John Bates, to the "Documents" section of my web site.)

More on this testing.

Just replaced my R/R with a 2005_barely_used one and this did not solve my problems.

I measured the output of my alternator @5000RPM
Y1= 78V
Y2= 78V
Y3= 50V

Ouch! looks like alternator stator failure.
Measured resistance: 1ohm for each winding.
Measured short to ground: infinite resistance between each terminal and engine case: no short.

I'll post some resistance measurings and diode testing on the R/Rs i currently own.

Sounds like you have some shorted turns on #3 phase, thats over a 25% difference in resistance and is significant.

Your average multimeter starts to become very inaccurate at much below 2 ohms and an  alternator winding resistance per phase can be as low as that of a 6" nail. To identify a sound winding ideally you need to measure and compare the inductance of each phase or you need a Milliohmeter or a "Ductor" to take accurate low resistance readings and then you must compare the differences in phase resistances as a percentage. For example the difference between 0.1 ohms and 0.15 ohms is not much on paper but when you do the sums its actualy 50%! Consider also if there is a breakdown between turns it may only be occuring at operating voltage/current, not the 3/6/9v and negligable current your multimeter operates on. Slightly higher or lower output voltages than stated as normal are common due to manufacturing tolerances, ambient temperature variations, old and weak magnets in the rotor etc and they dont confuse the reg/rect so long as each phase voltage is balanced, its only when there is a significant imbalance between phase voltages that the reg/rect becomes confused and starts running home to mummy.

Warning: this topic has not been posted in for at least 120 days.
Unless you're sure you want to reply, please consider starting a new topic.



I just wanted to know if you encountered problems with the low alternator voltage.
Did your battery lasted long after fixing the contacts?

I tested my system today and my output was about 60VAC.