13.5 Volts across battery..with bike OFF!!

[Big6ft6]

Nate...don't ya just love this stuff.:-D What model bike you got?? D or X
Not sure whats going on at this point...more questions than answers.
Do you have your high beam on during these tests?
Are you sure your connections are solid?
I have a on-board voltmeter to monitor my charging while riding...sometimes at lower speeds my bike may spike to 16v and set off the alarm (on the voltmeter). I turn on high beam until volts drop and than she's fine. How long are you testing for...may just be a spike and will lower while riding??

Hey Bret
I've got the sportier model with mag wheels (not spokes) yeah I have been testing with my high-beams on. I'm as sure as I can be about my connections, I don't get any voltage drops between battery and leads at the reg/rec.

I don't test for very long, I just turn the bike on, look at idle Volts (13.5), and then I twist the gas and the voltage shoots up with rpm to about 16-17 at 5000rpm, then I let go of the gas quickly. Is it possible that if I held it at 5000rpm the voltage would level off back to 14.8? I've never held it there for long just a second or so.

[Big6ft6]

Big6ft6,

Looking at your last entry alone (and relax, I have been reading the whole thread!), you would have to say that the reg/rect. isn't regulating the voltage output from the alternator.

Buuuut... are you *sure* the connections from the +ive and -ive leads (ie. red and black respectively) are good? I just ask this because in 'The Stator Papers' fault-finding chart here it talks about how one cause of high voltage is poor connections on these leads.

A related possibility may be that the earth from your battery to the frame via that chunky black lead isn't a good earth. In fact, this alone is the simple cause of many an electrical headache! Going back to these basics may well yield the joy you seek.

So I've got to ask with beby99,

All the best,
Mike.

Hey Mike

my grounds all seem to be in good shape, I don't get any voltage drops between battery and point where black or red leads head into the reg/rec.
And I'm running a ground directly to the r/r body from the battery.

I want to believe that my reg/rec is working appropriately and for some reason something is happening as rpms increase that make the r/r think it needs to allow more voltage through?? But I'm at a loss, I'm about ready to take it to the local motorcycle gurus and hope they can sort it out, or maybe tell me that nothing is wrong that everything is normal?

I'm so tired of electrical problems...I sold my first bike, GS750, 5 years ago becuase I couldn't stand riding around and waiting for it to shut down on me. And I CAUSED the problems on this bike by messing with stuff!

[Big6ft6]

Does anyone know where/how the regulators monitor voltage to see whether or not to let more or less through? Is it through the red wire?
Other bikes use a sensor wire....what does electrex have instead?

[tfb]

Yeah, I know the frustration and heartache that electrical gremlins can cause. I sold my first GS1000S years ago because of never-ending problems.

I don't get any voltage drops between battery and point where black or red leads head into the reg/rec.

Hmm, when testing the wiring, forget about voltage and instead check resistance (ohms) over the length of the wire. You can get a given voltage but stuff-all current (amps), etc.

So switch your multimeter to check resistance. A high resistance means that there is a poor connection somewhere, or even an internally frayed wire that should be replaced. And check the resistance between the negative battery terminal and the engine, too... that will tell you if the black earth lead is working OK or not.

[Big6ft6]

So get this, tonight I let my bike sit, engine off, with the high beams on for 45 mintues to drain the battery a little.

Then I hooked the starter relay back up (still off from when I was testing it) and started her up, now I barely get 12.5 volts at idle and I can just squeeze out 13.5 volts at drive 5000 rpms. Big difference from 17 volts I was getting before.

Is this just becuase my battery is drained some? Is this normal?

[tfb]

If you put your high beam on for 45 minutes, then your battery would be just about flat... so no wonder the voltage would be reading lower.

But, enough of that... have you checked the *resistance* of the various wires we've been talking about? :-\"

[Big6ft6]

If you put your high beam on for 45 minutes, then your battery would be just about flat... so no wonder the voltage would be reading lower.

But, enough of that... have you checked the *resistance* of the various wires we've been talking about? :-\"

tfb

I gues I assumed seeing no voltage drop along the wires would mean no increase in resistance? So I havn't actuall measured resistnace. What is a good resistance? What is too much?

I did do all the tests (including resistance tests) in the stator papers and all of the values were in line except I didn't do the diode tests of the r/r becuase I wasn't sure how.

[tfb]

You're after a resistance of zero. Infinite resistance means no connection at all. Anything in-between means a bad connection.

[GS850_Coug]

You're after a resistance of zero. Infinite resistance means no connection at all. Anything in-between means a bad connection.

Keeping in mind that there are no superconductors involved in the wiring harness, there should be "some" resistance across the wires. If there is less than 1 ohm you should be okay. More than that and there is definitely corrosion or a bad wire.

[chronoman]

I've checked my gs450 charging system today, and I get the same reading 17.6 at 1500 rpms and 13.5 with the bike off. battery about 2 months old.
Claude

1987 GS450l

[tfb]

GS850 Coug, right you are about the resistance being not quite zero for a good connection!

chronoman, 17.6 volts is not good! Go to the Stator Papers here on the GS Resources and follow them through systematically. Basically the high voltage is either a fried regulator or bad connections somewhere. Happy hunting.

[Big6ft6]

I've checked my gs450 charging system today, and I get the same reading 17.6 at 1500 rpms and 13.5 with the bike off. battery about 2 months old.
Claude

1987 GS450l

Chronoman...I'm so so so sorry...I will pray for you tonight.[-o<