electrical check?

[driftcreek850]

how do I know my battery is getting charged? The bike will run with out the battery, and I am getting 6-7 volts on the line with the bike running and the battery disconnected. Is this correct? If this is not, what do I need to replace?

[Steve]

Well, hopefully you did not damage everything by running it without the battery.

But, to check to see if it is charging, connect a voltmeter to the battery terminals and measure the voltage. A well-charged battery should show over 12.5 volts with the engine off. With the engine running at idle, voltage might get as low as 12, but should be about 13 or more. The test given in all the manuals says to check the voltage at 5,000 rpm, it should be between 14.0 and 15.5 volts. Most of us agree that 15.5 is too much for a standard wet battery, and you should read no more than 14.4 or so. An AGM (absorbed glass mat) battery will tolerate higher voltage, but should stilll be kept under 15.

If you do not see proper voltage at the battery, look in a document in the Garage section that is called The Stator Papers. It has a very good troubleshooting flowchart to help you pinpoint the problem.

.

[spyug]

Way too low friend and I hope you didn't leave the battery out or connect the bike to a car with the engine on to jump it as this could fry things.The battery is a necessary part of the charging circuit and not only stores energy but levels out the charge.

At 2500 rpm to 3500rpm or so you should see better than 14v. When the battery is fully charged it should show better than 13 v but drop to around 12.5v or so and stay there for quite some time ( better than a week at least).

You may have a bad stator or regulator/rectifier, the battery is junk or your grounds are not good enough. Before delving into the Stator papers check to see the battery is good ( make sure the fluid is to the line and or top up with distilled water) by putting on a 1.5 amp trickle charge over night. Check the voltage and as mentioned if it doesn't sit where I suggested it is likely bad.

If the battery seems good then a) clean the connectors at the battery terminals and the other end of the ground from the battery. You want a good clean metal to metal contact. b) attach a ground line from the R/R ( black/white) directly to the battery negative pole. Check the charging in that 2500/3500 range. If you are not seeing high 13s or better then you will need to work through the Stator papers for more tests and guidance.

Chances are about 50/50 on a bad stator versus a bad R/R but lets not jump to conclusions, lets narrow things down a bit.

Hope this helps. Report back when you check things out.

Good luck with it.

cheers,
spyug

[driftcreek850]

electrics

Well my 79 GS850 history is that someone hooked the battery up backwards and fried the wiring harness. I went through and replaced the grounds and repaired the damaged wires. Everything looks OK and works good on the brand new battery but the battery is not getting charged. So I should start with the rectifier? How do I test it? I guess I should check out your tech bulletin.

Thanks

[spyug]

I think you should start with the stator so have a look at the Stator Papers: http://www.thegsresources.com/garage/gs_statorfacts.htm

The stator is a bit more of a pricier project so if this checks out then you know its the R/R and Mr. Duaneage is the go to guy for a more robust one.

Do your homework and tell us what you're finding.

Good luck with it.

Cheers,
spyug

[driftcreek850]

Ok

Thank You, I will be working on it Saturday nite, I am a commercial electrician and most of this stuff makes sense to me and I have a petty pricey multimeter.. you know I got the bike for free and so it is making it easy for me to put a little $$ into it it only had 14K on it and it's turning out real nice. I have already had it out for a spin and I am amazed at how smooth of a machine it is out there on the road. I will post my results this coming week..

Thanks