View Full Version : Regulator problem w/3-brush gen.?
06-12-2006, 08:52 PM
I'm just putting a '46 Chief back on the road after a frame-up restoration. I've got a new/rebuilt generator and voltage regulator.
After a couple of test runs, I noticed that the brake light was getting pretty dim. I hadn't noticed the ammeter charging or discharging very much. (Everytime I checked it, it was sitting near dead center.)
I don't have an good ammeter, just the one on the bike, and don't have a very good voltmeter. So I just removed the band on the generator, and reattached the regulator in a way that allowed me to adjust the 3rd brush.
I've got the 3rd brush almost all the way back now and the ammeter on the bike registers about 1/3 to 1/2 the distance from '0' to '20' on the positive side of the guage at about 60mph. However, when I turn on the lights the needle drops to about 1/2 way between '0' and '20' on the negitive side of the guage.
Does this indicate a bad regulator? (My guess.) How can I trouble-shoot this? I'll go out and buy a good voltmeter or ammeter, if that's what's needed.
Any help greatly appreicated.
06-13-2006, 08:56 PM
Lets start with the basics. You sure you have a regulator? Usually a 46 just has a cut out. Is the base of the unit 1 inch by 3 inches and mounted onto the body with two screws or 3 inches by 3 inches mounted to the brush band with four screws? For that matter do you have a stock Autolite generator or something else? Since it's a fresh restoration did you make sure the generator has a good ground? Some people powder coat the generator body, mounting bracket and/or frame which is basically coating them with plastic and plastic is an excellent insulator ... Perry
06-14-2006, 12:01 AM
Its a regulator, 3x3 in. with two relays. It mounts to the band with 4 screws.
I have a ground from the generator to the transmission tower. So that's good. My ohm/volt meter is a RadioShack $9.95 special. Its not very accurate, but shows zero ohms to ground from the generator.
I'm not sure if its an Autolite generator, or just equvalent. I don't see any manufacturer's name on it, but its supposed to be a stock 3-brush 6-volt generator.
The one thing I have yet to double-check is the belt tension. It seemed pretty darn tight to me. I don't think it would be easy to get it much tighter, but I want to remove the belt cover, put a wrench on the pulley, double check that tomorrow, and then watch it with the motor running, while I turn on the lights to see if it looks like its slipping.
If the belt checks out, I'm wondering what I can check in the way of relay operation on the regulator to see if its doing its job.
Thanks for the help,
06-14-2006, 03:26 PM
My two cents. If the belt is too tight it will prematurely wear the gen bearings due to the pressure and your lack of oiling (hopefully not). Check your belt deflection. If it was/is slipping - replace the belt.
The regulator - regulates the current output. I'm not sure how the old manual regulators work. I think it may dump excess current via a relay. Is that right? This mechanical relay wears and fails over time, or through exposure.
Some V readings would be nice.
Is your battery charging? What current is flowing back to your battery for charging? Is your bike ammeter new? Is your tail light shorting out?
06-15-2006, 01:37 AM
I doubt belt tension is an issue if the generator is putting out with the lights off and you don't hear a squealing when you turn the lights on. You could always try some belt dressing (Gaskacinch is one I've successfully used in a similar application).
Sounds like you have the two charge regulator. This regulator doesn't fully determine the output since you still have a third brush whose position is the final arbitor of the output. The way the two charge regulator works is it has a carbon bar resistor on the side. It either grounds the field coils directly (full output to the max determined via the position of the third brush) or grounds the field coils via the carbon bar (partial output when the demand is low (eg: lights off)). First the regulator needs to be grounded in order to properly work. If the generator worked with the lights on but not with them off, I'd suspect the carbon bar was broken. However you've got the opposite problem. To trouble shot I'd probably bypass the regulator. Your generator has two wires coming out that connect to the bottom of the regulator. One to A and one to F. I'd disconnect the wire going to F and jumper it directly to ground. This will force the generator to full output. If you no longer see a discharge with the lights on you've got a regulator problem. Still see a discharge? - adjust the third brush. Still a discharge?, either a problem with the generator or you're running monster lights ... Perry
06-15-2006, 10:09 PM
Just to check... (I don't want to smoke anything.)
I'll ground the wire from the field. Then, since I have to remove the regulator, and I'm by-passing it anyway, should I connect the armature wire directly to the green wire (hot lead) from the ammeter?
Should I leave the armature wire connected to the A terminal of the regulator, and find a way to mount it with the band off the generator?
BTW, is it correct to check the voltage from the generator by measureing from the armature lead to ground with the motor running, and the armature lead not connected to anything (no load)?
Thanks for the help,
06-16-2006, 12:02 AM
You should leave the armature lead attached. You still need the cutout portion of the two charge regulator. If it's a problem disconnecting the wire, just leave it attached and jumper onto it and ground the jumper. You shouldn't run the generator without it connected to a battery. Do this much and you'll fry the generator. I'd suggest measuring voltage at the battery terminals ... Perry
06-17-2006, 01:08 PM
I've had a chance to make some observations and tests.
First a better description of my situation and assumptions.
The A lead is attached a relay on the regulator that has a coil magnet wound with very thick wire. It is normally open. I assume this is the cut-through relay. And that it should be operated (close) to provide charging from the generator.
The other relay, that the F lead is attached to, has a coil magnet wound with very fine wire, and is normally closed. It appears to ground the F lead when not operated (closed). However I'm not sure that's what this does, or when it should operate (open).
My battery is fully charged. When I took it off the trickle charger, it seemed like it was holding just under 6.5V. After I finished my tests (some charging, some discharging), it was holding at about 6.16V.
I made the following observations with the engine running at a fairly fast idle:
With the LIGHTS OFF, both relays "flutter", and voltage varies from about 6.5 to 6.15 volts. The ammeter varies from '0' to a slight charge.
With the LIGHTS ON, the "F" relay (the one with the fine coil wire) is solidly operated (open). The "A" relay (the one with the thick coil wire) flutters slightly, but is mostly operated. The ammeter reads about 3/4 of the way toward -20 (about -15?). The voltage varies from about 5.75 to 5.85V.
After the above tests, it occured to me that I have an after market sealed-beam headlamp that's probably the biggest drain when the lights are on. I disconnected it and found that, with the lights on, the ammeter only shows a slight discharge, maybe -2 - 3 amps (vs. -15 with the headlamp).
So I'm wondering...
Does this sound like the way that the regulator should operate?
Should a sealed-beam headlamp use that much current?
(Update: - I swapped my Motolamp with bulb for the sealed-beam unit. The Motolamp only used a couple of amps less than the sealed-beam. Still heavily discharging [about -12 amps]. So the problem is not related to the sealed-beam light.)
If you think I should still gournd the "F" lead to test the generator at full charge, should I leave the field lead attached to the F terminal, and run a ground strap to that terminal, or should I remove the field lead from the terminal ground it by itself?
Thanks for any help and feedback,
06-18-2006, 02:53 AM
The A relay with the thick wire is your cut out. At a fast idle and up it should be closed. It shouldn't be fluttering. Fluttering could indicate any number of problems from an out of round commutator, improper brush spring tension, armature going bad, etc.. Likewise the F relay with the fine wire should be closed with the lights on. With the points open the field coils are grounded via the carbon bar resistor on the side of the regulator. With the points closed the field coils should be directly grounded (eg: full output). If it was me I'd still do the grounding test (with the cover off the regulator just manually close the F relay's points) and see if the generator puts out enough at that point to keep up with the lighting demands.
Hard to say at this point whether it's a generator or a regulator problem. Certainly the regulator isn't behaving as expected but that may be due to a generator problem. You should probably have the pair checked over by someone competent at working on these units ... Perry
06-27-2006, 08:38 PM
I thought about how I could trouble-shoot this thing to either the generator, or regulator, and came up with the following...
Since the relay with the fine wire is the relay that regulates the output of the generator, I decided to run the bike with the relay forced operated, and then release it to see if it made a difference in the charging rate of the generator.
The coil on the regulating relay pulls the relay contacts open when it is energized. So I toothpicked the contacts open to simulate an energized relay. I started the bike and saw the nominal charge rate of just above zero, that I've been seeing lately. I pulled the toothpick and saw no change in the charging rate.
I checked the relay, and it was in an operated/energized state with the bike running. IOW the coil was energized, pulling the contacts open anyway, and that's why I saw no change when I pulled the toothpick. So, I forced the relay armature up, opposite the pull of the relay coil, and forced the contacts to close as they would if the coil on this relay were not energized. When I did this the charge rate jumped up by about 10 amps!
It seems like my problem is that the regulator relay is always operated thereby opening the contacts of that relay, and keeping the generator from charging at a high enought rate when the lights are on.
So, how's this regulating relay work? What's supposed to control when it operates, and when it releases? Does anyone know? If I can get it to operate (open the contacts and limit the charge rate) only when the lights are off, and get it to release (close the contacts and deliver a full charge) when the lights are on, I'll be good.
06-29-2006, 09:58 PM
Neither set of points should be "fluttering" (at least not on a TC style regulator). I don't know of a web site that gives a detailed description of how the TC regulator works, but basically the regulating relay works by sensing voltage drop (ball park figure is 1.5 volts change to get the points to operate). A different style of regulator has the points opening and closing hundreds of times a minute but not the TC style regulator. If working correctly it should be functioning as you desire (points closed with lights on or a low battery) and points open with lights off and a fully charged battery. I still suspect a generator problem at this point, especially given that the cutout points are "fluttering" ... Perry
Powered by vBulletin® Version 4.2.0 Copyright © 2013 vBulletin Solutions, Inc. All rights reserved.