interesting charging problem

[Guest]

ok my layout first.
aftermarket fuse box
R&R ground to battery
R&R positive to battery
headlight re-routed so it gets power direct from independent fuse via relay (dimmer switch controls relay)

now the problem

a couple months ago I upgraded to a electrex R&R due to the original regulator building up to a over charge with RPM
everything was text book perfect, it charged perfectly with voltage at idle of 13.8 and 14.5 at just above idle (2K rpm) two weeks ago while out on a ride with buddies I run into a no start issue and find the battery very low.
we find help at the local fire department and charge the battery, and I pull the headlight fuse (tail brake and all other lights stilll operate) and make for home.
once back on safe ground (IE= plenty tools) I discover that it is charging without the headlight fuse, put fuse in and the voltage starts to slowly drop again.
I determined that the charging system is making just above electrical system needs without the headlight.(a few watts) with the headlight it cant keep up.
I tested my stator output and got only 55 volts on all three legs, and resistance on all three legs was .4 ohm, both below specs, so I ordered a shiny new electrex high output stator.

I get the new stator today and install it and go over all the connections before firing the bike up, and everything checks out good.
I fire it up and get the exact same thing!!!!!
battery voltage before start up was 12.6 volts
running with headlight drops to 12.2 volts and is slowly dropping.
without headlight it came right back up to 12.6 and was slowly climbing, after a few minutes it was up to 12.8

fuses are all cool and all the correct range for the loads they handle. my amp meter is at work so I cannot confirm what is being used till Monday.
the only thing left is the rotor.
anyone ever hear of a rotor loosing its magnetism?? ( they seemed ok when I had it apart to put in stator)

[Anonymous]

Rare earth magnets can lose their magnetism via heat - but it has to be pretty hot. You can look up the temperatures for different materials on Google. I don't know what the rotor magnet is made out of (most today are neodymium, and it looks to be that color), but it would probably take some extreme, engine-damaging heat to burn out the magnetism.

Just a thought...

There's an assumption here that it's a properly-functioning headlight circuit that is overloading your charging system - reasonable given that the fuses are OK. But before you rule out some kind of short or malfunction in the headlight circuit, I would try to put some other kind of 12v load on the system and see what happens. A steady load like another 12v light would be best. If the system can support that load, but not the headlight, suspect the headlight.

However, another short somewhere else on the bike could load the system to the point that it can't support the headlight anymore. In that case, you'd charge if you d/c'd the headlight (reducing the load). And your charging voltage w/o headlight doesn't sound as good as it was before, so a "third-party" short could be your gremlin, too.

[earlfor]

I would check the AC voltage on the three legs of the new stator. If its putting out 80 v per leg at 5K rpm, its not a stator or rotor problem. I dont think the rotor losing its magnetism is probable. I would suspect the headlight relay. My experience is sometimes when they "go bad", they still function, but at a vastly increased amperage draw to operate the relay. I would try dropping the relay out of the headlight circuit and checking charge rate with the light wired directly and on hi beam at 5K.

Earl

[focus frenzy]

its not the headlight, I have already eliminated that.
it is barely making enough power to run the ignition and instrument lights and the LED tail light, with only a few watts for charging.
headlight is disabled. (pulled the fuse)

when it started this I tested the original stator and only got 55 volts on all three legs.
resistance on all three legs was .4 ohm.
both numbers below specs, so I replaced the stator, it is still not charging correctly.
I will be testing the new stators output shortly.

the only connection I can make is that I changed to mobil 1 synthetic motorcycle oil imediatly before this problem started, however I have no idea how the two would be connected.

[moto_dan]

Back in 1965 I had a honda 50 that had a magneto electrical system. Anyway the symptom was that the bike would run fine, but as soon as I turned on the headlight the engine would die. After about 2 weeks of trouble shooting the shop had tried everything and then the owner who worked on aircraft in WWII remembered that occasionally the rotor(permanent magnet) would lose it magnetism(sounds like me at 55) so as a last resort they replaced the rotor and to everyone surprise it cured the ailments. So, how does this apply? It doesn't, but I got to tell an old story

[focus frenzy]

update!!
it apears that the two month old regulator is at fault.
I have one test left to do (the continuity of the stator to case test) but stator output was good (75 volts all three legs)

[Anonymous]

Leon, how is your regulator connected? I goofed when I put mine in by not paying attention to the directions sent and found I was drawing too much off it. An electrician friend helped me eliminate unnecessary connections. My regulator was heating up too hot to touch after a few minutes of use before he corrected the problem. The higher the heat the less voltage it puts out. I also added a Computer case fan (remember me showing it to you?) on the RR and that also aids in maintaining temperature and proper voltage. Just my 2 cents....

[duaneage]

At least the RR is under warranty from Electrix.

The type of magnet that loses it's charge is an ALNICO. Alnico magnets must be recharged because in the presence of an electric field they lose the magnetism. Ferrite magnets do not lose their charge. After the civil war in Zaire in 1977 cobalt was hard to obtain and manufacturers switched to Ferrite for speakers. Alnico is not a good choice for rotors because of temperature sensitivities, it is doubtful that any of our GS bikes came with a alnico rotor.

[focus frenzy]

well after actually going through the complete stator pages I can say without a doubt that the stator pages are flawed.
it has no test for the actual regulator side and does not recognize a fault with the regulator, just stator and rectifier (diode) are covered.
if your stator and the rectifier are ok, the stator pages states that nothing is left and your battery is bad. BULL HOCKEY!!!

my problem is the regulator, my stator is good and the rectifier is good, the regulator is not letting power through.
like the old saying goes, "you get what you pay for" I should have bought a Suzuki regulator, the original lasted 25 years.

[Anonymous]

Leon you still have your rectifier on it?? Dude the electrex replaces both the regulator and the rectifier 8O

[Redman]

Leon, You saying that your requlator is a seperate item from your rectifyer? Or just that the regulator portion of the R-R is faulty?

[focus frenzy]

Leon, You saying that your regulator is a separate item from your rectifier? Or just that the regulator portion of the R-R is faulty?

the regulator portion of the R/R is faulty.
in a very similar way to that of the original one, it is stuck at a level that is not allowing enough current through to the battery for charging.
the old one was stuck where it was charging perfectly at about 3500 rpm, below about 3K rpm it was not charging, and above 4K rpm it was over charging (15 volts and above) and I discovered that if the Rpm went above 6K rpm it would suddenly go into a dead short. (not good)
that is why I replaced it.

[duaneage]

I bought a Honda regulator for 7 dollars shipped on eBay.

It's true what they say about Honda Regulators, they work better.