I have a motor with a 6 volt generator and separate regulator, with a 6 volt negative ground battery. I had trouble with no charging, and had the generator and regulator tested by a qualified repair service. I was told everything was okay. I replaced the equipment, polarized the generator, and upon startup, the ammeter was cyclically moving up and down and the lights were blinking. I was asked to return the regulator, and again was told it was working correctly, and had been tested under load. Upon reassembly, polarizing, and starting up, the ammeter cycled less, but with higher rpms, the ammeter was cycling in the high end of the range and and then dropped to negative, and the lights dimmed. I cleaned and reassembled the battery terminals, and that didn't change anything. I got a brand new replacement regulator, polarized the generator again, and the ammeter is completely still, and doesn't move with higher rpms, suggesting no charging. I checked the continuity of the wire from the regulator through the ammeter to the battery, and it's fine. The armature and field terminals on the genrator are okay, and are continous to the regulator, but are also connected to ground. Is this normal. Not sure where to go from here. Any suggestions?
6 Volt generator/regulator
- Thread starter wrede
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Soundguy
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a circuit or b circuit.
look at the old reg, flip it over... if there is a bias resistor from ground to field, then it is a circuit.. if there is a bias resistor from armature to field ( may be another as well ).. then it is B circuit.
polarize a circuit by jumping bat to arm(gen)
polarize b circuit by jumping bat to fld
you can bypass regulator cutout by jumping bat to arm, then full fielding the generator:
a circuit, jump fld to ground
b circuit, jump bat to fld
should make max charge.
if no, then shut down and slip belt off.. and motor test genny.
a circuit: jump fld to ground, jump bat to arm
b circuit: jump bat to fld and arm
genny should spin.
post back
soundguy
look at the old reg, flip it over... if there is a bias resistor from ground to field, then it is a circuit.. if there is a bias resistor from armature to field ( may be another as well ).. then it is B circuit.
polarize a circuit by jumping bat to arm(gen)
polarize b circuit by jumping bat to fld
you can bypass regulator cutout by jumping bat to arm, then full fielding the generator:
a circuit, jump fld to ground
b circuit, jump bat to fld
should make max charge.
if no, then shut down and slip belt off.. and motor test genny.
a circuit: jump fld to ground, jump bat to arm
b circuit: jump bat to fld and arm
genny should spin.
post back
soundguy
Will run test the generator later today. It's an "a" circuit regulator. I disconnected the wires, and checked the continuity of the field, generator, and battery wires, and they are all good, and not shorted to ground. The field terminal on the generator is shorted to ground. Is that correct? The armature terminal on the generator is shorted to ground as well. Is that correct? Thanks for your help.
Soundguy
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think about it... the wire in that genny isn't many ohmsa and will look like continuity from the field (brush) to the armature..e tc.
remember on an a circuit, armature provides field power and the vreg provides field ground.
and between arm and ground is not much more than a ball of copper....
soundguy
remember on an a circuit, armature provides field power and the vreg provides field ground.
and between arm and ground is not much more than a ball of copper....
soundguy
I made the bypass the test you suggested, that is jumpering the armature to battery wires, and grounding the field wire. The generator develops a full charge according to the ammeter, and the ammeter doesn't jump around, nor do the lights blink. So, it appears the generator is good, and the ammeter is good. The old regulator is bad, despite two tests/adjustments by an "expert", and the brand new regulator is also bad. Seems like a strange coincidence, but what else could it be? I'm taking the old and new regulators to another recognized shop and have them checked out. Thanks again for your detailed suggestions and "how it works" explanation.
Soundguy
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you can test a regulator cutout with a vom , 2 6v batteries and a charger.
put charger on one battery.. hookup battery grounds to each other, and regulator ground to bat ground.
put hot wire from bat with charger to arm tab on battery.
put vom across other battery.. it should read 6.3v. now hookup bat tab on reg to hot on other battery. voltage should go up, and then go back down if you turn the charger off. this will tell you if the cutout is opening and closing when charge comes up on the arm side.
testing field can be done with an ohm meter.
there is a bias resistor between field tab on the vreg and ground.. this provides some field current when vreg field tabs are open.. when vreg field tabs are closed, this resistor is shorted, effectively providing full ground to the A circuit field coils. howver it don't stay like that usually, and instead 'vibrates' back and forth quickly to make an 'averaged' charge.
there are machines for testing genny and regs.. and other more in depth tests for better machines like growlers for the armature.. etc. but for basics.. this stuff works..
soundguy
put charger on one battery.. hookup battery grounds to each other, and regulator ground to bat ground.
put hot wire from bat with charger to arm tab on battery.
put vom across other battery.. it should read 6.3v. now hookup bat tab on reg to hot on other battery. voltage should go up, and then go back down if you turn the charger off. this will tell you if the cutout is opening and closing when charge comes up on the arm side.
testing field can be done with an ohm meter.
there is a bias resistor between field tab on the vreg and ground.. this provides some field current when vreg field tabs are open.. when vreg field tabs are closed, this resistor is shorted, effectively providing full ground to the A circuit field coils. howver it don't stay like that usually, and instead 'vibrates' back and forth quickly to make an 'averaged' charge.
there are machines for testing genny and regs.. and other more in depth tests for better machines like growlers for the armature.. etc. but for basics.. this stuff works..
soundguy
After much testing and adjusting, by an experienced auto electrical guy, the voltage regulator is working okay. The cut-out relay is apparently a very sensitive adjustment, at least on my regulator, and after repeated tests he got it to settle down. I have it running, and it seems to be okay, showing full amps right after starting, and then settling down to a slight charge when running, and there is no more dramatic needle bounce or flickering lights. Hope it's good for the long term.
Soundguy
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at least until you replace the vreg 
having a good compensated gauge might help too.
good luck
soundguy
having a good compensated gauge might help too.
good luck
soundguy
OrtisEvans
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Are "a circuit" and "b circuit" terms used here just to make the reply more clear, or are they commonly used descriptors?
Always trying to get smarter - and sometimes succeeding
Always trying to get smarter - and sometimes succeeding
The "A" and "B" circuit are the terms used to describe the two types of voltage regulators commonly seen. "A" circuit generator field coils are grounded by the voltage regulator contacts (typically Delco). "B" circuit generator field coils are internally-grounded, and the regulator supplies voltage, not ground to the field coils. I found this by Googling the subject.