PDA

View Full Version : 6 Volt Charging Problem



motive
12-29-2005, 12:23 PM
Ran the battery down trying to restart my Speedster. Jumped it according to the accepted method and got it running. Since the battery was very low, the ammeter showed full charge as expected. As I continued to drive the car for a while on my way home, it remained at full charge and I began to notice a faint "electrical" smell entering the cabin. Shortly after this the ammeter rapidly went from full charge to slightly negative, showing a slight discharge. Made it home safely, started the car the next morning and it appeared normal at idle with a slight positive charge on the ammeter. BUT... as I increased engine speed the ammeter moved to full charge and rapidly dropped to the slightly negative position, never to return to the positive side again. Clearly it is not charging anymore. I tried connecting a voltmeter across the "Gen" and "Field" terminals of the genertor with the engine idling and observed no measurable voltage. I have not yet checked the generator brushes, but I removed the regulator cover and everything looked and smelled fine. Any comments or suggestions? Should I have seen voltage across the Gen and Field terminals? Any help will be greatly apreciated.

Mike with Speedster

N8N
12-29-2005, 12:46 PM
test for voltage at the "gen" terminal to ground, should be somewhere around 7V running. If it is, say, 5.9 or thereabouts then your gen. is not charging. So you need to figure out why. Check for voltage between "field" and ground. Should be some small voltage. if none then your regulator is bad. if some voltage then it sounds like the gen. is bad, but to check for sure, while the engine is idling jump "bat" to "field" then you should get a high (greater than 6) voltage between "gen" and ground. If not then the generator is definitely bad. Leave lights, radio, etc. off while full-fielding or you will let the smoke out.

good luck

nate

--
55 Commander Starlight
62 Daytona hardtop
http://home.comcast.net/~njnagel

motive
12-29-2005, 12:57 PM
Nate: Thanks for the help. I measured voltage from GEN to ground and got zero, FIELD to ground and got zero. So I'm thinking that the generator is dead. At least I now know where to start.

Mike with Speedster

N8N
12-29-2005, 01:18 PM
What happens when you full field it? if there's no voltage on the field terminal it won't charge...

nate

--
55 Commander Starlight
62 Daytona hardtop
http://home.comcast.net/~njnagel

Roscomacaw
12-29-2005, 01:35 PM
You'd better have a GOOD look at the connections on the back of the ammeter.[}:)]

Miscreant at large.

1957 Transtar 1/2ton
1960 Larkvertible V8
1958 Provincial wagon
1953 Commander coupe
1957 President 2-dr
1955 President State
1951 Champion Biz cpe
1963 Daytona project FS

motive
12-29-2005, 03:45 PM
Mr. Biggs: Do you think that the smell was coming from the melting insulation on the wires to and/or from the ammeter and that the ammeter connections might have been loose/corroded and of high resistance? I'll be sure to check them!

Mike with Speedster

Roscomacaw
12-29-2005, 03:53 PM
I can't be that specific from this chair. But obviously something was getting warmer than it should be. I'd damn sure check those connections before I ran the car again.;)

Miscreant at large.

1957 Transtar 1/2ton
1960 Larkvertible V8
1958 Provincial wagon
1953 Commander coupe
1957 President 2-dr
1955 President State
1951 Champion Biz cpe
1963 Daytona project FS

motive
01-01-2006, 12:09 PM
I checked the ammeter leads and they look fine, no indication of melted insulation or overheating. With the engine idling, no voltage from GEN to GRND. Took off the generator band, cleaned the commutator, checked the brushes (which looked good), still no voltage from GEN to GRND. Removed the generator from the car and spun it on rapidly the bench with a socket and drill. GEN to GRND gave me < 1.0 volts, FIELD to GRND the same. I show continuity between GEN and FIELD, between GEN and housing, and between FIELD and housing. Shouldn't something be isolated. I'm not an electrical guy and this is my first experience with generators, so I'm not very informed. But I expected to see approx. 7.0 volts from the GEN to GRND when I spun it on the bench. Looks like this generator may have burned up during the extended high charging. I hate to throw parts at something, but I'm thinking a rebuilt generator and a new regulator may be the answer. Any recommendations for suppliers?

Thanks, Mike with Speedster

55s
01-01-2006, 01:08 PM
Mike:

By correct way to boost, it would be positive to positive and negative to negative, regardless of the fact that the Speedster is 6V negative ground. In other words, the negative ground of the 12V car goes to the 6V negative terminal, and the positive 12V goes to the 6V positive ground. In any case, watch it, because I have had a 6V battery explode whan I boosted it.

If its any consolation, 6V starting is always slower than 12 V starting.

Besides looking for a short on the back of the ammeter, check the back of the starter switch (in the dash), the terminal block under the hood on the radiator, and the wiring coming out of the steering column for shorts. Also, make sure those 55 dash switches are turning on and off cleanly.

I don't think you have done anything to damage the generator. I'd try to get some local help to diagnose before spending money on spare parts.

Alternately, you should always have spares to keep your car going - so maybe now is the time to invest in spares - if the new set doesn't work, you'll have a spare. But it does sound as though you have a short problem to resolve first.

Goodluck.

Paul

ceecab
01-01-2006, 01:56 PM
By correct way to boost, it would be positive to positive and negative to negative, regardless of the fact that the Speedster is 6V negative ground.

Except that a '55 is 6V positive ground-- including Speedsters

Roscomacaw
01-01-2006, 03:03 PM
motive,

Without having a battery and voltage regulator "on the bench" as well, you're going to see very little voltage [:I] (like ONE volt.[:o)])
The voltage regulator looks at the output of the generator and then sends the field winding the appropriate amount of grounding to cause the generator to meet the demands of the electrical system. (The other end of the field circuit is connected to the Generator's A terminal and gets it's "hot" side there.) The field winding uses that metered ground to build a variable magnetic field. The spinning armature cuts thru that magnetic field and in so doing, produces the voltage that runs the electrical items on the car and charges the battery so that there's power to run things even when the generator's not spinning.
Consequently, without the regulator to send the field a signal, and without the battery to provide a load - you've gonna see a very minor voltage when just spinning the generator on the bench.;)
That you see anything AT ALL, is due to the fact that the steel core's of the field windings have retained some magnetisim from the time when said windings were energized. This residual magnetisim, minor tho it is, is enough to generate SOME voltage in the armature as it spins. Consequently, only one volt (or thereabouts) output.[V]

As to your question "shouldn't something be isolated" - the answer is no. Not in this generator. The field and the A terminal should read to the case. Not as zero ohms, but they will show a reading.;) This is due to how it's wired internally. Remove (unseat) the one brush that's connected (grounded) to the case. If you still have continuity with this bursh displaced/or removed, then you've got an internal short.

An alternator and a generator are actualy working in the same ways essentially. The difference is that the windings of the spinning armature of a generator become the stator (stationary ) windings of the alternator. The field windings (the stationary windings inside the generator's housing) of the generator are replaced by the rotor (rotating windings) of the alternator.

I'd like to ask if you've visually checked all the connections on the regulator. Tight?, no evidence of overheating?
Where is the battery cable from the battery's positive terminal grounded? Is it grounded to the engine or???[?]


Miscreant at large.

1957 Transtar 1/2ton
1960 Larkvertible V8
1958 Provincial wagon
1953 Commander coupe
1957 President 2-dr
1955 President State
1951 Champion Biz cpe
1963 Daytona project FS

motive
01-01-2006, 03:32 PM
Jumped it positive to positve, negative to negative, touching the negative of the Speedster with the jumper cable only while the starter was cranking. There are no visible signs of shorted wires under the dash at the ammeter or the ignition switch, or at the ternminal block on the fan shroud. All connections at the regulator appear clean and solid. System was working perfectly until after the jump, when the high charge rate appeared to last longer than necessary to charge the battery. Battery still has charge after driving it home and it sitting about a week. Shows 6.1 across terminals.

Mike with Speedster

motive
01-01-2006, 06:03 PM
Positive terminal of battery is grounded to engine using a heavy woven metal strap. There also is another much shorter grounding strap connecting the engine to the frame at the lower front right side of the engine. I tried removing the two brushes from the generator and still saw continuity with the housing although now there was measurable resistance across each terminal to the housing. Also removed the regulator and checked/adjusted point gaps etc. per owners manual. Everything was pretty close to spec. Re-installed everything, polarized generator, started her up and still no charging. Ammeter shows discharge that changes with load, so I know the ammeter is working. Just can't get it to show positive charge. Another item to mention, there are two small condensers (capacitors) in the system. One is mounted on the generator housing and is connected field terminal of the generator, the other is mounter on one of the regulator mounting bolts and is connected to the Battery terminal of the regulator. One may be for radio noise suppresion?, the other to stop arcing across the points of the regulator? Shop manual really doesn't show or mention these at all. No numbers on them that I can see. Although it's probably unlikely that these are involved, I'd still like to know what purpose they serve. Thanks And Happy New Year.

Mike with Speedster

N8N
01-01-2006, 07:15 PM
I don't believe the suppression cap should be on the field terminal, rather it should be on the "A" terminal... but I doubt that is your problem. take it out of the system completely for now until you are done troubleshooting, that way if it is bad you will know it when you hook it back up

nate

--
55 Commander Starlight
62 Daytona hardtop
http://home.comcast.net/~njnagel

motive
01-02-2006, 12:40 PM
I'll take it out of the system. One other quick question. With the ignition switch in the OFF position (key removed) I see battery voltage at the BATTERY terminal of the regulator. Is this normal or should I only see it when the ignition is in the ON position? Seems odd that it would remain hot all the time. I need a wiring diagram!

Mike with Speedster

55s
01-02-2006, 12:44 PM
CEECAB is of course correct - Speedster is 6V positive ground. I wrote a very wordy answer, and then improperly edited it. Sorry. Fortunately, my second sentence is right. In any case, it seems as though it was boosted properly.

I just checked my 55 Commander coupe. There is no condenser on the generator. It has a radio.

I have no idea what is causing your charging circuit woes. You seem to be doing all of the right stuff.

Good luck.

Paul

jackb
01-02-2006, 05:53 PM
I'm going to make a guess that you've cooked something inside your generator....Pull it out, take it apart...check all internal wires, make a sniff around, clean things up in there....it will only cost $10. for brushes, bearings etc...well maybe a bit more, but unless you know the condition of them, they're suspect. Case in point, a local member was taking his pristine 53' to SB a few years ago. Car had been total frame-on resto....low mileage original. Generator burned out on the highway in NY......remember these things are 50+ years old.....

N8N
01-02-2006, 06:20 PM
motive,

ask and ye shall receive.

https://www.studebakerparts.com/studebakerparts/parts/html/pages/wirediagrams.html

I know there's not one for a Speedster on there, but really the only difference from a Commander is behind the dash, so the '55 Commander diagram should tell you what you need to know. I would look and see if there even is a separate Speedster wiring diagram in my shop manual, but it's in the back seat of my car, 20 miles away :(

Yes, the "BAT" terminal is straight to the battery; it gets disconnected from the armature by the cutout relay in the regulator, so when the gen. is not charging nothing happens, but the wire itself is always hot.

If you decide to give up and take it to an auto electrical shop, I would take the generator and regulator in together. That way they can adjust the regulator for you once they've figured out what the problem is and have fixed it.

good luck,

nate

--
55 Commander Starlight
62 Daytona hardtop
http://home.comcast.net/~njnagel

motive
01-02-2006, 08:12 PM
Ok, I Full Fielded it (Field jumped to BAT)and saw zero volts from GEN to GRND. Loks like something fried in the generator. Thanks for the wiring diagram and all the advice. I think I will pull the generator apart and take a look. I'll let you guys know how it all turns out. I'd just like to have figured this out more quickly, as I'm really enjoying driving this car!

Mike with Speedster

Roscomacaw
01-05-2006, 10:21 PM
Mike, where did you get the instructions for your "full fielding"? The reason I ask this is that I'm guessing you were attempting to repolarize the generator? OR were you trying to put full voltage to the field to see if it would cause the generator to put out anything? Either way, your assumption/attempt was wrong. The feild terminal gets a controlled GROUND - not hot feed.
The shop manual for 1955 shows how to RE-polarize a generator by touching a jumper between the B & G treminals of the regulator. The manual stresses EXTREME caution that this be done and done right lest you reverse polarize the generator which will destroy the regualtor.
Again, as I said in my earlier post, the field circuit of the generator is fed a controlled amount of ground - not hot.:D

Miscreant at large.

1957 Transtar 1/2ton
1960 Larkvertible V8
1958 Provincial wagon
1953 Commander coupe
1957 President 2-dr
1955 President State
1951 Champion Biz cpe
1963 Daytona project FS

motive
01-17-2006, 06:19 PM
Sent both generator and regulator off to HITE Parts Exhange. They tested the generator and it was fried. They are rebuilding it, replacing the armature and field coils, etc. 1-Year warranty. They also tested the regulator and said it was bad also, but provided no additional information (I was talking with someone other than the repair technician at the time). I suspect that the regulator may have malfunctioned and failed to limit the generator output as it should have (kind of "stuck closed") and the extended period of time the generator was "loaded" resulted in it overheating and damaging wiring, solder, field coils, etc. HITE is also providing me with a replacement regulator. Should have everything back in about a week or so and be back on the road.

Mr. Biggs: I thought that you needed to excite the field coils by providing voltage to them to get the spinning armature to generate output. So "full fielding" it would be applying full voltage from the BAT terminal of the regulator to the Field terminal of the regulator. If you supply ground to the field terminal the regulator the field coils won't be getting any voltage and nothing would happen. This is not consistent with what you said, so now I'm confused. Isn't the GEN terminal of the generator (and regulator) the generator output, and doesn't grounding the FIELD terminal to varying degrees control the ouput by varying the strength of the field (with total ground resulting in no output and full battery voltage (full field, no ground) full output? Even though it's going to be fixed, I'd still like to know how it actually works.

Thanks, Mike S.

motive with Speedster

Roscomacaw
01-17-2006, 07:32 PM
Mike, Do you have a 55 shop manual? If so, look at the section title "Polarizing the Generator" on page 14 of the Electrical section. This says that it's important to repolarize the generator after ANY work's been done to the charging system. And this is to be done AFTER all components are back in place and all wiring hooked up properly. Also, it's to be done BEFORE the car is started!
You simply take a jumper wire and momentarily touch it (ever so briefly!) between the B & G terminals on the regulator. (Talking Delco stuff here - it's the A & B terminals for Auto-Lite components as you'd find on 6 cylinder models.)

To your question - the field winding gets it's "hot" power from the end of it that's NOT connected to the "Field" terminal. It does so because that other end of the field winding is attached (inside the generator) to the "hot" brush that rides the armature. The regulator controls the field's GROUND thru the generator's F terminal - not HOT. :D

Let's hope your rebuilt or renewed components do the trick.

Miscreant at large.

1957 Transtar 1/2ton
1960 Larkvertible V8
1958 Provincial wagon
1953 Commander coupe
1957 President 2-dr
1955 President State
1951 Champion Biz cpe
1963 Daytona project FS

motive
01-18-2006, 01:25 PM
Thanks Mr. Biggs. I'll be sure to polarize the generator prior to starting the car. Ok, so the field coils get their hot from the "hot" brush riding on the armature, and the field strength is controlled by the regulator varying the resistance to ground from the FIELD terminal of the gnerator. So does the "hot" brush initially get it's voltage from the battery to the BAT terminal of the regulator and then through the GEN terminal of the regulator to the GEN terminal of the generator to the "hot" brush? Does the current reverse through this path when the generator is charging, with the generator output going back through the regulator to the battery? If so, then once the field initially becomes excited and the generator begins to produce current, does the spinning armature generate the current that feeds the "hot" brush and keeps the field excited, as the current reverses in the GEN to BAT to battery circuit? If so, then you only need the current from the battery to initially excite the field, and after that the system generates it's own potential, which is regulated back to the battery.

Do I have it right yet?

Thanks,

motive with speedster

Roscomacaw
01-18-2006, 03:14 PM
In essence, the generator's gonna provide the very initial excitation to begin charging - I think you've got a fair handle on that. And, of course, once the generator's putting out - even barely - the field WILL be using "hot" from the hot brush while the other end of the field is regulated by having it's ground continually modulated by the resistence offered-removed by the regulator as it senses demands of the car's electrical system.
There IS the phenomenon of "residual magnetisim" in the field windings. That is to say that once the iron poles of the field windings are magnetized thru the fields being energized, said field poles RETAIN a bit of magnetisim. This magnetisim CAN induce a current in the generator if the F terminal is grounded while the generator's spun.
This residual magnetisim is actualy initialized when you do the "polarizing" manuver we talked about earlier. "Polarizing" meaning, in essence, affixing an initial orienting of the magnetic fields in the field poles so that the generator doesn't try to output a voltage that's of opposite polarity to what the car's oriented for.[xx(] Such would ruin a regulator's contacts in short order as it wrestled with trying to work the generator AGAINST the battery!:(

Miscreant at large.

1957 Transtar 1/2ton
1960 Larkvertible V8
1958 Provincial wagon
1953 Commander coupe
1957 President 2-dr
1955 President State
1951 Champion Biz cpe
1963 Daytona project FS

wray
01-18-2006, 09:12 PM
BECAUSE THE BATTERY WAS DEAD, YOU HAD A FULL FIELD CONDITION WICH MORE THAN LIKELY THROUGH THE SOLDER OFF OF YOUR ARMATURE.AND POSSIBLY RUINED YOUR REGULATOR. HAVE THE GEN. CHECKED WITH YOUR REG. BY SOMEONE WHO'S FAMILIAR WITH IT. IF YOU CANT FINDE ANYBODY I CAN HELP YOU I OWN AN AUTO ELECT. IN SAN DIEGO

motive
01-20-2006, 01:57 PM
wray: That's exact what appears to have happened, as the regulator tested bad and the generator needed to be rebuilt with a new armature. I haven't received them back yet, but I believe the wiring in the car is undamaged and everything should be back to normal with the new parts. Thanks for the input!

Mike with Speedster