Charging too much?

On my '82 the Voltage across the battery terminals is 14.7v at idle and 14.8v at 3000rpm. Does that voltage seem high at idle?

Shure does , Maybe check with another meter just to be shure

I don't know. The digital voltmeter on the 85 Interstate shows 15 volts at 3000 rpm (60 mph). I do have to add distilled water to the battery frequently.

Agreed that charge is too high for idle. Checking with another meter is a great idea. If it still reads high I would suspect the reg sense wire is not getting the full voltage to read.

I dunno. If it never actually overcharges, i.e. goes unregulated over 15V, why is it a problem putting out similar numbers at idle as when up to speed? It certainly won't hurt anything. Could be normal for this combination of stator and regulator components. They might just be super efficient - although it IS more typical for charging voltage to fall back at idle. I'm just not sure I'd be concerned if it didn't.

You'd think though if it were normal it would have been noticed sometime in the last 30 years.

[url=https://classicgoldwings.com/forum/viewtopic.php?p=184296#p184296:2fvsjjb5 said:

slabghost » Tue Nov 29, 2016 4:24 pm[/url]":2fvsjjb5]
Agreed that charge is too high for idle. Checking with another meter is a great idea. If it still reads high I would suspect the reg sense wire is not getting the full voltage to read.

Click to expand...

I'm pretty confident in my multimeter accuracy. Where is the sense wire and how would I check the voltage on it?

[url=https://classicgoldwings.com/forum/viewtopic.php?p=184294#p184294:1dh8znyq said:

PurpleGL1200I » Tue Nov 29, 2016 4:21 pm[/url]":1dh8znyq]
I don't know. The digital voltmeter on the 85 Interstate shows 15 volts at 3000 rpm (60 mph). I do have to add distilled water to the battery frequently.

Click to expand...

Yes, PurpleGL, I have to watch the water in my battery too. Has almost gone dry a couple of times.

Looks like the black lead at the reg/rec plug.

If the voltage on the sense wire is lower than battery voltage it causes the regulator to charge the battery more.

[url=https://forum.classicgoldwings.com/viewtopic.php?p=184304#p184304:237tv7ad said:

slabghost » Tue Nov 29, 2016 5:31 pm[/url]":237tv7ad]
If the voltage on the sense wire is lower than battery voltage it causes the regulator to charge the battery more.

Click to expand...

So, why wouldn't it then also manifest itself with a higher than normal charge voltage at 3K RPM?

Increased input should result in increased output through higher resistance wiring so at higher rpm the 15 volts in will be sensed to be 12v and regulator will seem satisfied is my guess. Check the test recommended by the book here.

According to the book at the last link I posted it is normal. You're good!

Should sense wire voltage be checked with engine running? Anyways, I went out and took the RR plug apart. With engine not started I measured voltage across battery terminals at 11.9V. Voltage between black sense wire and neg battery terminal at 11.7V.

Did I do the test right? Is the difference of .2V be enough to make much of a difference?

Shouldn't make much difference but still at idle it should be lower is my guess. According to what I've been reading since your first post though. My guess is it's acceptable.

Concur. You're chasing ghosts. Ride it. But bundle up. It's even cold in Arizona now. Only got to 58F today. That's cold for us.

OK, thanks guys :thanks: