Blowing headlamps

[tkent02]

So if Tkent never used a Honda unit, kept his bikes charging in descent order, the regulator section of the R/R may very well have never failed on any of his bikes as temperature is the dominate failure mode for the R/R.

Don't know if that's it. Where I live now its generally not too hot, but an engine running at full throttle all the way up a 13,000 foot pass has to get hot. I lived in Arizona and California for years and rode in the desert a lot, done quite a few long rides that were EXTREMELY hot. Most of my GS miles were around Seattle but with a lot of rides to Eastern Washington where it gets hot.

Most of my GSes have been eight valve models which don't run as hot, but have had several sixteen valvers too, no problems with them either.

A few of them may have had the Honda units but I never put them in.

[bobgroger]

From my detailed analysis on the subject, the only way to over charge is either

1. you have an old R/R that only controls one leg of the stator.
2. the regulator portion of the R/R has to go bad.
3. You put a 6 wire Honda R/R sense point in a really bad place(low voltage point WRT battery voltage).

Other than 3.) above Dirty connections CAN NOT cause over charging , they always result in UNDER CHARGING.

So if Tkent never used a Honda unit, kept his bikes charging in descent order, the regulator section of the R/R may very well have never failed on any of his bikes as temperature is the dominate failure mode for the R/R.

It seems to me that a bad RR ground connection would not allow the RR to shunt the excess output to ground, causing overcharging....

[posplayr]

It seems to me that a bad RR ground connection would not allow the RR to shunt the excess output to ground, causing overcharging....

Explain that in terms of ohms law. I don't think it is possible other than how I described.

[JMHJ]

As alluded to in a couple of the other posts, by the time you lose your headlight, your battery is probably almost dry, so don't neglect making that right as part of your R/R troubleshooting.

That's been my experience anyway.

[bobgroger]

Explain that in terms of ohms law. I don't think it is possible other than how I described.

A shunt regulator shunts excess voltage to ground. No ground, no shunt, no regulation. With Ohm's law, resistance to ground increases, current flow (regulation) decreases. Go undo the ground to your shunt RR, I'll bet the charging voltage goes way up.

Unless the RR is also grounded through the case, in which case forget what I said.

[posplayr]

A shunt regulator shunts excess voltage to ground. No ground, no shunt, no regulation. With Ohm's law, resistance to ground increases, current flow (regulation) decreases. Go undo the ground to your shunt RR, I'll bet the charging voltage goes way up.

Unless the RR is also grounded through the case, in which case forget what I said.

As you increase resistance between the r/r and battery the current flowing from the r/r to the battery causes voltage drops which lower the teminal voltage of the battery below that of r/r (+). Likewise with the return burrs t from the negative side of the battery going back to R/r(-) the is also a voltage drop. Making the battery ground always higher than R/r(-). So no matter how much resistance to get the battery can't over charge. Now if you remove the battery or make the resistance so high at some point the r/r will possibly run up in voltage trying to pass some current but I suspect that is device dependent.

Unless you have a single scr regulator or the mid installed Honda, under all conditions of moderate inline resistance the r/r should not over charge.



If you draw a simple diagram of r/r battery and series resistance this wi be clear once you figure out that all current returns to r/r(-) and not ground.

[bobgroger]

Thinking more about it, if you remove the ground you also remove the return path for the bottom 3 diodes so charging voltage would decrease at least half at the same time.

[posplayr]

Thinking more about it, if you remove the ground you also remove the return path for the bottom 3 diodes so charging voltage would decrease at least half at the same time.

if you remove the R/R(-) ground there is not current flowing through either the stator or the the R/R.

R/R(-) is completing the circuit for current flowing out R/R(+) (rectified from the stator) to return back to the stator through R/R(-) and the completion of the full wave rectification that the R/R does.

You can also see that if there is no connection between the output pair of a full wave rectifier, there is no way for current to flow from the 3 phase source. So again, if you remove one leg (e.g. R/R-) there will be zero current flow.