14 replies [Last post]
312Icarus
312Icarus's picture
 Offline
Joined: 07/15/2016
Posts: 332

My '68 has a charging problem. It won't quite charge the battery. The genny seems to put out ~6.2 volts with the light on. New brushes and new brush springs haven't helped. Cleaned the armature etc. Question is, what is an easy test to see if it is the regulator or if the genny is just tired? My books are not clear as to how to test output pre regulator.

In my limited experience with generators is that they generally work or not, assuming they are putting out near proper voltage. If they put out only 1/2 or no voltage that begins to explain things, but putting out near proper voltage begins the mystery.

Anybody have a simple series of test procedures? My short term fix has been just to ride it, and plug it into a small solar panel when I'm home. After a couple of days of riding the voltage has dropped to ~6.1-6.2.

Icarus

PS. The battery is just a year old, and hold a proper charge once fully charged, ~6.35-6.4 vdc.

wa1nca
wa1nca's picture
 Offline
VBMWMO #8374
Ashfield Ma.
Joined: 09/27/2012
Posts: 358
Bypass voltage regulator

You can bypass the voltage regulator to force the generator for its max output
Connect your volt meter to the battery
The F terminal on the regulator should have 2 wires connected to it
One is from the field winding and the other goes to the resistor
Disconnect both and Briefly ground the yellow wire going inside to the field housing
It then should put out its max output ( you also need to bring the rpm's up above idle)
You should see the voltage increase on your voltmeter
Don't do this for to long as the voltage may go above 7 volts and burn out your headlight bulb if on
If the voltage does rise then your regulator is not working properly and should be replaced

Tommy

__________________

Tommy Byrnes
54 R51/3 55 R50 64 R27 68 R69US 68 Sears Allstate 250 (Puch)

312Icarus
312Icarus's picture
 Offline
Joined: 07/15/2016
Posts: 332
Thanks...Ill give it a

Thanks...Ill give it a whirl.

Icarus

312Icarus
312Icarus's picture
 Offline
Joined: 07/15/2016
Posts: 332
Over 8 vdc at high idle.

Over 8 vdc at high idle. Thanks. Now, can Ifigure out how adjust the regulator?

312Icarus
312Icarus's picture
 Offline
Joined: 07/15/2016
Posts: 332
So I cleaned the contacts on

So I cleaned the contacts on the regulatory with 400 emery cloth, then contact cleaner and air. Now at ~2000 rpm, with the headlight on, I'm seeing just about 7 volts. Make done the trick. It may be a few days before I can ride again to confirm.

Thanks

Icarus

wa1nca
wa1nca's picture
 Offline
VBMWMO #8374
Ashfield Ma.
Joined: 09/27/2012
Posts: 358
Low charge voltage

You are fast
I was going to suggest your regulator contacts may need to be cleaned so the field wire gets a good ground when needed
Light clean with emery cloth, contact cleaner, and then air
7 volts with your headlight on
Doesn't get better than that

Tommy

__________________

Tommy Byrnes
54 R51/3 55 R50 64 R27 68 R69US 68 Sears Allstate 250 (Puch)

312Icarus
312Icarus's picture
 Offline
Joined: 07/15/2016
Posts: 332
I fully charged the battery

I fully charged the battery this afternoon, so now I have it sitting with the signals on to drop the voltage below where it has previously been. Gonna go for a short ride tonight to see if it comes back in. Will report.

BTW, one really ought not use Emorycloth (even though I did, and I was told that years ago!)as the hard bits can get trapped in the points. Doing a bit of reading suggest 360 grit sand paper, drawing it gently through the points, with a bit of alcohol on it. I used 400 and electrical contact cleaner.

Thanks for all the (continuing) advice,

Icarus

312Icarus
312Icarus's picture
 Offline
Joined: 07/15/2016
Posts: 332
Verdict...well after a ten

Verdict...well after a ten mile ride, the voltage only comes back up to 6.2, same as before. I guess I will take the regulator off again, look closer at the contacts and give them another (better?) cleaning.

Icarus

Daves79x
Daves79x's picture
 Offline
VBMWMO #9030
Joined: 08/09/2015
Posts: 304
I Fought

I fought the original regulator for a while when I got mine running, finally gave up and installed an electronic one - easy and works just fine now.

Dave

__________________

Dave

312Icarus
312Icarus's picture
 Offline
Joined: 07/15/2016
Posts: 332
Dave,I hear you, but I'm

Dave,

I hear you, but I'm both cheap and stubborn! Not always a good combination. It drives me batty when simple things that ought to work, don't quite.

Icarus

schrader7032
schrader7032's picture
 Offline
VBMWMO #7032
San Antonio, TX
Joined: 10/27/2006
Posts: 6540
But it's nearly 50 years

But it's nearly 50 years old!! Gotta factor that in...

__________________

Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

312Icarus
312Icarus's picture
 Offline
Joined: 07/15/2016
Posts: 332
^I hear you, but it is

^I hear you, but it is falling off a log simple. The coils and the core work fine, it is just a matter of getting the contacts right. I noticed that an "original" VR is over $500! Not likely.

I think I am on the path to having it right, but I'll let you all know.

Icarus

wa1nca
wa1nca's picture
 Offline
VBMWMO #8374
Ashfield Ma.
Joined: 09/27/2012
Posts: 358
Electronic regulator

I have seen them somewhere for 70.00
Other sites the same one goes for 170.00
Twocams from Oregon just replaced his a I think he paid 70.00
If you cant make it work then I would ask him we he bought his
PS If you connect the battery backwards it will burn the electronic regulator out

Tommy

__________________

Tommy Byrnes
54 R51/3 55 R50 64 R27 68 R69US 68 Sears Allstate 250 (Puch)

Captonzap
Captonzap's picture
 Offline
Joined: 08/21/2014
Posts: 55
Icarus is right. By careful

Icarus is right. By careful manipulation of the spring controlling the voltage, you can adjust the output.

http://www.snafu.org/restore/uandm_bmw_v1.pdf

Page 11-14 will give you some tests to check the voltage, and try an increase of spring pressure on the voltage coil and see what it does to the voltage. Adjust from there, plus or minus. Gently, since it doesn't take much adjustment to change things.
CZ

312Icarus
312Icarus's picture
 Offline
Joined: 07/15/2016
Posts: 332
^Thanks for the link...I had

^Thanks for the link...I had seen it before but had forgotten it. Mine seems to be charging actually, but I need a longer ride to get it fully charged.

Icarus

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.