3 brush Not Charging

awander
Senior Member
Posts: 2082
Joined: Fri Sep 21, 2007 3:03 am
Bikes: '52 FL
'64 FLH
Has thanked: 163 times
Been thanked: 511 times

Re: 3 brush Not Charging

#16

Post by awander »

Sam:

The 3rd brush energizes one field coil.

Turning the lights on energizes the other coil.

I suspect a wiring error either inside or outside of your generator.
Scrap
Senior Member
Posts: 824
Joined: Fri Jul 03, 2009 7:07 am
Bikes: 1957 FL
1980 FLT
74 FXE
2017 road glide
1971 Bonneville
2021 Ural GU
Location: Pawtucket
Has thanked: 248 times
Been thanked: 124 times

Re: 3 brush Not Charging

#17

Post by Scrap »

awander wrote:Sam:

The 3rd brush energizes one field coil.

Turning the lights on energizes the other coil.

I suspect a wiring error either inside or outside of your generator.
I'll check wiring. Thanks. Does that mean the third brush adjustment has no effect on the output with switch in position one (light off)? What about the readings I got with the lights on. Should the output drop off as the RPM's increase? Is 7 amps at idle OK?
Thank you,
Sam
windweaver
Member
Posts: 122
Joined: Fri Jun 18, 2004 8:03 am
Bikes: 49 HD
Has thanked: 4 times
Been thanked: 2 times

Re: 3 brush Not Charging

#18

Post by windweaver »

did you polarize it? WW
Scrap
Senior Member
Posts: 824
Joined: Fri Jul 03, 2009 7:07 am
Bikes: 1957 FL
1980 FLT
74 FXE
2017 road glide
1971 Bonneville
2021 Ural GU
Location: Pawtucket
Has thanked: 248 times
Been thanked: 124 times

Re: 3 brush Not Charging

#19

Post by Scrap »

windweaver wrote:did you polarize it? WW
Yes
awander
Senior Member
Posts: 2082
Joined: Fri Sep 21, 2007 3:03 am
Bikes: '52 FL
'64 FLH
Has thanked: 163 times
Been thanked: 511 times

Re: 3 brush Not Charging

#20

Post by awander »

Scrap wrote:
awander wrote:Sam:

The 3rd brush energizes one field coil.

Turning the lights on energizes the other coil.

I suspect a wiring error either inside or outside of your generator.
I'll check wiring. Thanks. Does that mean the third brush adjustment has no effect on the output with switch in position one (light off)? What about the readings I got with the lights on. Should the output drop off as the RPM's increase? Is 7 amps at idle OK?
Thank you,
Sam
When the lights are off, the "regulating" field coil is energized through the 3rd brush. The 3rd brush should be adjusted to charge the battery at "about 4A maximum charging rate". (but nobody ever says at what engine speed). I prefer to set it so that it charges at about a max of 3A.

When you turn the lights on, the second, "shunt" coil is energized. This is in addition to the first coil, so the 3rd brush will still have an effect on charging rate.
From idle, the output will increase with increasing engine revs up to a point, and then will begin to fall off as you go higher in RPM.

I think 7A at idle is way too much!...but, are you sure that was not negative 7A(discharge of teh battery? My bike will not charge at all at idle.
Scrap
Senior Member
Posts: 824
Joined: Fri Jul 03, 2009 7:07 am
Bikes: 1957 FL
1980 FLT
74 FXE
2017 road glide
1971 Bonneville
2021 Ural GU
Location: Pawtucket
Has thanked: 248 times
Been thanked: 124 times

Re: 3 brush Not Charging

#21

Post by Scrap »

awander wrote:
Scrap wrote:
awander wrote:Sam:

The 3rd brush energizes one field coil.

Turning the lights on energizes the other coil.

I suspect a wiring error either inside or outside of your generator.
I'll check wiring. Thanks. Does that mean the third brush adjustment has no effect on the output with switch in position one (light off)? What about the readings I got with the lights on. Should the output drop off as the RPM's increase? Is 7 amps at idle OK?
Thank you,
Sam
When the lights are off, the "regulating" field coil is energized through the 3rd brush. The 3rd brush should be adjusted to charge the battery at "about 4A maximum charging rate". (but nobody ever says at what engine speed). I prefer to set it so that it charges at about a max of 3A.

When you turn the lights on, the second, "shunt" coil is energized. This is in addition to the first coil, so the 3rd brush will still have an effect on charging rate.
From idle, the output will increase with increasing engine revs up to a point, and then will begin to fall off as you go higher in RPM.

I think 7A at idle is way too much!...but, are you sure that was not negative 7A(discharge of teh battery? My bike will not charge at all at idle.
Using a "Fluke" digital meter on the 10 Amp scale, with the RED meter lead to the positive battery terminal (black meter lead in series to the batt. wire), switch in position two with the high beam on I read positive 7 amps at idle. As I increase the RPMs the amperage goes down, if I roll the throttle on, I can actually get the reading to go to zero and then start getting negative readings! I have a toggle switch on my headlight, if I leave the switch in position two (energizing the shunt coil) and turn off the headlight with the toggle switch, i read 3.8 amps at idle. Amperage also goes down as RPMs go up. If I reverse the leads on the meter, I get the same readings but with reversed polarity. As I said in the previous post, in position one, the third brush setting has no effect on output, 1.5 amps at idle or higher RPMs. Could a mistake in my wiring or a bad ground be the problem?
awander
Senior Member
Posts: 2082
Joined: Fri Sep 21, 2007 3:03 am
Bikes: '52 FL
'64 FLH
Has thanked: 163 times
Been thanked: 511 times

Re: 3 brush Not Charging

#22

Post by awander »

Hook the ammeter up with the bike not running.

Turn the lights on and see whether you get a negative or positive reading.

You should get a negative reading. If positive, reverse the meter leads.

Then take all of your readings again with the meter hooked up this way.
1951 adam
Senior Member
Posts: 889
Joined: Mon Apr 02, 2012 5:35 pm
Bikes: 1951 panhead , 1995 dyna
Has thanked: 116 times
Been thanked: 47 times

Re: 3 brush Not Charging

#23

Post by 1951 adam »

You can also pull the generator and motor it, that will tell you if your coils are wired correctly. You do not polarize a 3 brush , check the service manual for detailsHow to Motor a 32E Generator

1, connect negative post of battery to body of generator

2, connect positive post of battery to relay terminal of generator

3, give the gear a twist in the direction of normal rotation (counter-clockwise when vied from drive end) and it should motor in that direction. If you have to fight the gear to rotate or it rotates in a clockwise direction you have the "Regulating Field Coil" wires reversed. Switch the leads and try again.

4, add a jumper wire between the "relay terminal" to the "switch terminal" the generator should continue to motoring. If generator stops dead and won't turn you have the "Shunt Field Coil" wires reversed. switch the leads and try again.

To check the field coil polarity connect battery to coil and hold a magnetic compass near coil. This will show north & south pole orientation. Make sure the two pole magnetic fields are in the same direction. If I remember correctly "Regulating Field Coil" South Pole points towards armature and "Shunt Field Coil" North Pole points towards the armature.

Have Fun with it.
Post Reply

Return to “Generator”