R/R twilight zone

[elbandtioCA]

so just when i thought i might finally be trouble free for a little while....

my bike keeps frying R/Rs.  I first noticed the charging system was acting weird a few months ago.  The battery was slowly getting weaker.  The mechanic said it looked like a bad R/R was causing a key-off short.  So he ordered me a new one from an aftermarket supplier and I installed it.  But with the new R/R in the bike the voltage wasn't staying constant at all.  As the battery was very old I put a new in.  The mechanic told me that it looked like the R/R wasn't working properly--perhaps I shorted it out when installing because I foolishly didn't disconnect the battery.  So he ordered another, and this time I made sure to install it with the battery disconnected.  After that, the charging system seemed to be fine--a steady 14 volts.  A few weeks later, I decided to check it again, just because I'm paranoid, and guess what, the voltage wasn't being regulated--revving the bike up the voltage went up to ~18 volts. 

Now I'm not very knowledgeable about electrical systems, as you can probably tell.  But my mechanic insisted that it couldn't be anything but a bad R/R.  He had another used one lying around the shop, and he suggested I plug it in to give it a try.  I did, and once again this seemed to fix the problem--14 volts steady.  So he let me keep it, and for the next week or so I checked it every day and it was fine.  That was about three weeks ago.  Last night I noticed the nights were acting funny, so I checked, and the regulator isn't working!!! spikes up to 18v

Does anybody have an idea of what is frying these R/Rs?  Is this a problem anybody else has had with their b4.  Obviously I don't want to just stick another unit on the bike...  But I don't know the next test to perform.

[tomacGTi]

If the RR fried your old battery and you're still using that, there's a chance that it could be smoking all those RRs.

Run the Electrosport test in Stormi's sig and go from there. It's pretty much true to form, it found my problems when I was having voltage issues.

[elbandtioCA]

i'm using the new battery--I installed at the same time as the second new R/R that I put on the bike.  So the bike was burning R/Rs before this battery went on.  Just out of curiousity, how does a bad battery damage a R/R?  Also, where is this article of Stormi's? 

[tomacGTi]

A bad battery can overwork the RR to charge it, cooking it.

http://www.electrosport.com/electrosport_fault_finding.html

[elbandtioCA]

randy-thanks for the link.  i've seen that flow chart before, but i hadn't remembered to download a copy. 

it seems weird that the battery would be bad, as I put a new one in at the same time that a new R/R went on the bike.  but is there any way to test the battery to see if it is ok?  the charging system flow chart assumes that I have a good battery in the first place.

also, is there any possibility that a bad battery alone would be causing the voltage to shoot up so high, or does this certainly mean that whatever else is wrong, I also need a new R/R.  My mechanic told me I should pay the 150 bucks and put in a OEM one to try if that works, but I'd rather be more confident about this as the fix before spending the  $.

[tomacGTi]

A bad battery can read 12v but will not put out enough amps to turn the bike over because of sulfication from overcharging (boils out the acid and the plates short). I would say take it out of the bike and bring it to an auto parts store or the moto shop to see if they can load test it for you. I don't know how to load test myself, lest I would say how.

When my RR died a year or so ago, it took out a good gel cell battery and I was pissed (they're expensive!). I had no idea what was going on until I went through the flowchart step by step and found the RR to be the culprit. My symptoms were that the bike would start (barely) and then the battery wouldn't have enough ass to restart if it needed too (had to pushstart it if it didn't catch right away) even after 10 minutes of riding. The headlight would constantly glow brighter and dimmer and the turnsignals would be weak and strong intermittently.

Testing at the battery terminals revealed 12v not running (though not enough amps to crank since the battery was toast from overcharging) and at 4k it was 18v where it should have been around 14.1-14.7 IIRC. That was with the original RR from 1991.

I'm currently using a newer GS500 RR as it was plug and play (same exact plugs) although I have read that the GS and SV suffer from the same fate of burning out RRs. Some SV guys actually put in GSXR ones and adapt the wiring instead with the thought being that they have a bigger heatsink and can cope with the excess power from high revs coming from the stator. That's my next option if it craps out again.

To help out the new RR, I placed an additional ground inline to the battery in the wiring as well as another ground from battery negative to the mounting bolt of the RR. Figure it couldn't hurt and additional grounds helped out in the car, why not the bike?

[elbandtioCA]

your story is similar to mine.  when i installed the new battery and the second new R/R at the same time, I also put in a ground wire from the neg. output of the R/R back to the neg terminal of the battery.  It seemed to be charging perfectly.  But just now I used the flowchart from electrosport and made it all the way through to the end without any problems (other than the fact it doesn't seem to be regulating voltage...18v at 5k rpm).  according to the electrosport chart, this means my battery is at fault.  but... on the phone with the guy who sold me the R/R(s) he said that the test only checks the rectifier portion, and that there isn't really a test for the regulator.  so I'm wondering if
a) that is true, and
b) if that is true why the electrosport chart doesn't say anything about that, and
c) if a) is true how can you tell the difference between a bad regulator and a bad battery?   is taking the battery somewhere to have a load test done the next thing for me to do.

On the other hand, I wonder if I am frying the regulator when I rev the bike up very high.  When I put the latest unit in the bike and it seemed to work just fine, I hadn't taken it out on the freeway at a high RPM.  In fact, I kept checking it for about a week and it seemed to be fine, but if I think back, it was only after that I went out for a long ride and really wound the bike up to about 12k rpms (usually, when commuting I don't ride like that).  so maybe i'm killing these things only at a high rpm?  is this a known problem with the b4s?

[tomacGTi]

Trust me, my bike has bounced off the limiter more times that I care to remember since installing the new-to-me RR. This includes a ridiculous day in the saddle last October where we were out for 16 hours, most of it on the limiter.

I've checked it since then and it's still regulating (and I hope it continues to do so). The factory manual I think goes over checks for the regulator itself. I'm pretty sure you can ohm it out to go through it.

I'd get the battery checked out first, just to make sure and rule it out for sure.

[gsxr400 racer]

I do the extra ground thing when i run a RR. On my race bike i got tired of this all together and got rid of the whole charging system i sure like the revs now and how quick it spools up but i dont ride that one on the road...

[elbandtioCA]

i'm pretty close to just tearing the whole charging unit out 

i've checked the shop manual and it doesn't give a specific test for the regulator (as opposed to the rectifier).  it just has a table of values with different resistances, and also says that you won't get an acurate reading without a "suzuki pocket tester."  in fact, my voltmeter shows OL resistance where I'm supposed to be getting 3.5 ohms, according to suzuki's table.  but on the electrosport diagram (and its an electrosport R/R I have) the directions say to use the diode check function.  when i do that, i get the right values: ~.5 volts. 

but regardless my understanding is that these tests only check the rectifier portion, and that the regulator may still be bad.  i'm almost sure that my battery is screwed now, so i'm going to try all this with a better one, but that doesn't explain why a new battery only lasted 1 month in my bike...

[gsxr400 racer]

ideas why it only lasted a month:

was it fully charged from the get go?

the bike charging will never fully charge a new battery and just put a big strain on it...

those test are for the whole RR unit pretty useless.

another thought which has happened to me recently is my meter was not good the batteries where dying and it was not reading voltage right...

[elbandtioCA]

interesting what you say about the R/R tests being useless.  I'm starting to wonder this myself.  I just read the electrosport PDF on "diode testing" your R/R, and upfront they state that this test only really checks the rectifier side, and that it requires special equip to test the regulator circuit.  but they also say that "usually" when a R/R fails it is the diodes of the rectifier.  BUt in my situation this "usually" isn't helpful, as I keep putting new R/Rs on the bike that don't seem to regulate voltage, but they pass the diode test--I even just checked the old one that I thought was bad and it passes the electrosport test.   

Now I guess I'm trying to determine whether its the untestable regulator circuit or the battery.  What you say about the new battery makes me wonder...I got it from the guy who sold me the R/R and he charged it up to get it ready.  And in fact, when I put it in the bike the charging system seemed to work fine.  Are you suggesting that a new battery will run down on its own even if the charging system is working? Not sure if understood what you mean by "the bike charging will never fully charge a new battery and just put a big strain on it..."

I'm going to recharge the battery and try all of this again.  I know my meter is good because I just bought it yesterday and it has a new battery of its own...

[gsxr400 racer]

what i mean about the battery is most shops not all are in a hurry and most fill with the acid and give it to the customer then you put it in your bike it fires up OK then the reg rec works to get it up to full capacity also if the battery is charged you will see o rise in voltage if it needs charged it will jump to 14-16+ have the battery load tested as stated

[elbandtioCA]

ok, i'll get it load tested.  but do you mean that it will jump to 14-16 volts when i try to charge it with the trickle charger, or it will jump that high when the bike is running and i measure the voltage? 

[gsxr400 racer]

ok, i'll get it load tested.  but do you mean that it will jump to 14-16 volts when i try to charge it with the trickle charger, or it will jump that high when the bike is running and i measure the voltage? 

While it is in the bike charging on the bike voltage at 5000 rpm you may see 14-16+ volts if the battery is low... Common thing to see when the reg rec goes bad is the light bulbs blowing out starting with turn signal bulbs maybe a headlight or the lights get bright as you rev or the cdi goes pop