Originally Posted by Epic_Diesel
After thinking about it, That must be the voltage regulator. How can i test it to see if its good or needs replacing?
you need a voltage reader...heres a breakdown some guy posted (i was having a similar problem with my daytona 955i() hope this help...
This is about replacing the standard equipment Regulator/Rectifier with a more efficient component. You can do this in event of failure rather than replace with the same stock component, or you can even do as a preventive measure if desired.
As a prologue, let me introduce a basic troubleshooting process to determine whether you have a charging system failure.
A good Multi-meter is a pre-requisite.
Record your battery voltage under the follow conditions
1) Ignition off, unloaded battery.
2) Ignition on, headlights on, not running
3) Bike started, running at idle
For condition 1, should be at least in the high 12.x range if fully charged.
In condition 2, your voltage should not drop much below 12.0 at worst. (It may continue to drop – hopefully slowly! – as your lights will be discharging it. However this should be a slow decline)
If it does drop immediately into the 11’s, your battery is insufficiently charged – if it was just charged from a battery charger however, then it indicates your battery no longer has sufficient capacity to retain charge/supply current to load and should be replaced.
Condition 3 is what we are most interested in with respect to charging capability.
Voltage should be at least in the 13’s at all engine rpm. You may detect it will fall off slightly as you raise engine rpm. This is not atypical performance. A simple mod that can enhance your charging voltage to the battery can be achieved by this modification outlined in this thread. That should give you performance in the 14V+ range.
What if you have less than 13V?
First thing to check is the fuse in the charging circuit. Ask on the forum for your particular model which one you should check if in doubt.
Next, examine the wires and connectors between the stator output and the R/R input (three wire harness and connectors) – are these charred/melted due to excessive heating? This is fairly common result of poor connection between the mating terminals. See later in thread for examples of this issue & suggested replacements.
A ‘cold’ resistance check for shorted diode/SCR:
Unplug both input & output plugs from R/R;
With your meter set to read resistance (use a diode test if the your multi-meter has one), test from each pin of the three pin plug, to both the red & black wired pins of the 4-pin plug; NONE of these should read short circuit (zero resistance); depending which way you bias the test leads, you may get some reading (from the forward bias of the component) but it must absolutely not be a short. If you see a short on any of these readings the R/R is defective.
Next, do a resistance check on the stator (check at the cable connector going back towards the stator itself).
Measure between the three respective combinations of the three pins:
This time each of these should measure almost short circuit (very low resistance in order or about 1 ohm)
This next check is probably the simplest/quickest way of determining a stator problem - in majority of cases a bad stator will be indicated by failing following test:
Check resistance from any one pin to the engine ground terminal – this should not read any indication – maximum resistance or open-circuit.
If you read ‘short’ in that last test, then your stator is bad.
(if open, it is not quite guaranteed your stator is good however - but in majority of cases a failed stator will fail this isolation test)
Check the AC voltage output from the stator with engine running:
Leave stator disconnected from the R/R and start the engines.
With meter set to read AC Volts check
All three should be the same value – any significant difference of one reading will indicate a bad phase and the stator is probably defective.
At idle this should be ~ 20V* and rise to ~ 70V* at 5K rpm.
I hesitate to use absolute numbers here as this can be different between models and test equipment and especially the engine rpm!
What you are looking for is same value between phases and like increase on each phase as rpm increases.
If any of the above tests raises suspicion, pull the cover & inspect the stator. It is simple to do and can set your mind at ease by seeing what it looks like. Hopefully NOT with 1/3 of it a black charred mess!
If you have to replace the stator and R/R, especially because of a shorted R/R and excess current drain, be especially careful to ensure that your wiring has not been compromised. Replace any cable &/or connector plug that is not in optimum condition.