Bad Voltage Regulator ...OR?

theharleydr

.020 Over
Joined
Dec 24, 2012
Messages
12
Location
MESA AZ
Voltage regulator tested bad, replaced, still no charge.
New full battery,
the service manual tells how to check ACV output which proved to be in spec, BUT.., a grounded stator will show good ACV output until loaded. As soon as you are connected and running you are loading the stator. Thus dim headlights and charging voltage lower than battery resting voltage.
Turns out all three legs show continuity to ground.
Any short cuts to pulling the motor?
AGAIN!
Did the trans update kit at 20k, new clutch at 30k now new regulator and stator at 33k.
Oh yea fuel pressure regulator at 6k.
:inlove my rocket loves me.
 
...
the service manual tells how to check ACV output which proved to be in spec, BUT.., a grounded stator will show good ACV output until loaded..

I would contest that statement
Even un-loaded you will see a lower voltage on the phase that actually has the short to ground, versus the other two.
It should be discernible
The key is that you measure the voltage on the three phases at the exact same engine rpm (idle is simplest for consistency)

Turns out all three legs show continuity to ground.
It will ALWAYS be the case that you either measure ALL short to ground, or NONE short to ground.
It is not possible for any of the three to read differently regarding resistance to ground as you simply read the 'good' coils to the bad one and resistance between all three is less than an ohm anyway, even when perfect.

But the fact is, you measured short to ground from your stator, so that says it is toast.

With the cost and horrendous amount of work to replace the stator on a Rocket, I would consider trying a Series R/R:
I have an SH847 model R/R from a VStrom 1000 on my Daytona
These are plug n play with the Same connectors as the OEM Shindengen FH012 - very similar form factor, but slightly taller heatsink.
(or you could try a Compufire, but the Vstrom unit will essentially plug n play*)
* ensure the added height is not an issue.

The SH847 is a Series R/R, whereas the OEM is a MOSFET Shunt R/R.
The difference in short, is:
with a Shunt R/R, your stator is producing maximum current AT ALL TIMES, with the excess being expended in the Shunt.
with a Series R/R, only the current being demanded by the load (i.e. the bike's actual electrical system) is being pulled from the stator.
Therefor the stator runs much cooler and does not try to fry itself.

You can read more on that here - Triumph Forum: Triumph Rat Motorcycle Forums - View Single Post - Charging System Diagnostics - Rectifier/Regulator Upgrade
 
Wow. For the uninitiated, a prophylactic change of stator would seem to be in order. What is involved, and is there a better time to do it than another ?
 
I would contest that statement
Even un-loaded you will see a lower voltage on the phase that actually has the short to ground, versus the other two.
It should be discernible
The key is that you measure the voltage on the three phases at the exact same engine rpm (idle is simplest for consistency)


It will ALWAYS be the case that you either measure ALL short to ground, or NONE short to ground.
It is not possible for any of the three to read differently regarding resistance to ground as you simply read the 'good' coils to the bad one and resistance between all three is less than an ohm anyway, even when perfect.

But the fact is, you measured short to ground from your stator, so that says it is toast.

With the cost and horrendous amount of work to replace the stator on a Rocket, I would consider trying a Series R/R:
I have an SH847 model R/R from a VStrom 1000 on my Daytona
These are plug n play with the Same connectors as the OEM Shindengen FH012 - very similar from factor, but slightly taller heatsink.
(or you could try a Compufire, but the Vstrom unit will essentially plug n play*)
* ensure the added height is not an issue.

The SH847 is a Series R/R, whereas the OEM is a MOSFET Shunt R/R.
The difference in short, is:
with a Shunt R/R, your stator is producing maximum current AT ALL TIMES, with the excess being expended in the Shunt.
with a Series R/R, only the current being demanded by the load (i.e. the bike's actual electrical system) is being pulled from the stator.
Therefor the stator runs much cooler and does not try to fry itself.

You can read more on that here - Triumph Forum: Triumph Rat Motorcycle Forums - View Single Post - Charging System Diagnostics - Rectifier/Regulator Upgrade
I wonder if one should install the Series R/R prior to the stator crapping its self....
 
Wow. For the uninitiated, a prophylactic change of stator would seem to be in order.

Prophylactic Paul? :D
Your autocorrect on steroids?
I'm thinking that was maybe intended to be 'proactive'

If indeed what you meant then I would say no, not a good idea to replace stator proactively
However I would certainly say the R/R IS (if you go to a Series type) - even on a well used stator it will go to work immediately in prolonging stator life
 
I wonder if one should install the Series R/R prior to the stator crapping its self....

Definitely!!!
That is why* I have it on my Daytona and I don't have to pull the motor to change MY stator!

*; purely to improve the reliability and defer potential replacement stator costs
 
Let me try to succinctly explain series vs shunt regulstion;
A shunt regulator will draw the maximum current that the stator is capable of producing at any given engine rpm - it supplies that current through two parallel load paths - some to that demanded by the bikes utilized current and the rest via the 'shunt' in the R/R itself; as the voltage rises, that is how it regulates by effectively 'shorting' the stator with the shunt path

There is no shunt in a series regulator - it works like a switch in-line (series) between the stator and the load - instead of directing that extra current to control the voltage, the controller 'opens' the switch to disconnect the load.
So the series will only every draw whatever current is asked by the load - this is about half of that pulled by the shunt system
Half the current would translate to one quarter of the power expended (square of the current)
So stator is cooler and less prone to fail

See the link I posted above for thermo images that support the theory
 
Understood how it works . . . the first time. Trying to get to the specifics of what and how to install on the Rocket. :)
 
Back
Top