The generator on my old car doesn't charge the way it should. The light will be on dim, or flicker on and off at lower speeds. It is worse with the lights on. Sometimes it will go out after I speed up a little, and sometimes not. Today I had to rev it up until it sounded like it was going to sling the rods out of it before I could get it to go out. After I finally get the light to go out, it seems to be charging properly, and it will be OK until I shut it off and then it begins all over again. I have had it in the shop to be rebuilt, twice, but these guys don't know how to work on this old stuff. One of them even admitted he sent it somewhere else after I dropped it off. Maybe it's time I learned to fix it myself, but I don't know what I am looking at. It doesn't have the old style voltage regulator with the adjustments any more. I replaced it with a new one from Napa and it is the solid state type. I know why all the old heads replaced them with alternator s , but I wanted to fix it if I could. Looking for help or suggest ions
I've never seen a solid state replacement for the old style voltage regulators but most solid state stuff is polarity sensitive. I think I would take a real close look at the armature in the generator and see if the comuntator bars are worn down and make sure the brushes and springs are in good shape. Next, disconnect the wires and remove the fan belt. Jump from the battery to the big post and the generator should run smoothly like an electric motor. Sadly most shops call blowing out the cob webs and replacing the brushes a rebuild.
Its a 12v set up right ? because if i remember correctly chevy switched to 12v in 1955 but used generators. and ive notest that most generator parts are 6v because there more common. and it might not charge correctly if its only putting out 6v
http://www.jalopyjournal.com/forum/threads/1953-210-12v-with-original-generator.994644/ you said back in 2015 ----- I went and looked @ my 55. The body of the generator has the step-down in it and the tag reads : Delco-Remy 1100324 1C21 12V The regulator I am running is a NAPA Echlin VR122 I'm not making any claims about these being correct for make/model/year but they are working together. Good Luck
This tread may not get into this topic on regulator's because it's likely not the issue at hand since the regulator is solid state. Topic, "thermal environment" within the regulator. I read about this a little to late and the project got away so I never got to play around with how temperatures affect how a regulator works. Thought I'd bring it up because as OP stated. This type of charging system isn't common anymore.
You are right, I did post that. Thanks for the reminder. They were working until recently. No parts have been replaced since then. I dug out my 55 shop manual did some reading. Pretty good cookbook troubleshooting guide and explanation of how the system is supposed to work. I did learn a few things, including I was wrong about the idiot light and that I have not been cleaning the commutator on a regular basis. Right now its out in the dark, in the rain, with a dead battery. Tomorrow is another day. Thanks to all for the comments.
Look up "moss motors generator to alternator conversion" on youtube. I just switched mine out for a alternator and it's cheap and easy to do
Are you certain it is solid state? Sure looks like a mechanical regulator to me. Try connecting a jumper cable from the G terminal to battery ground post for test purposes. It's also important that the regulator itself, the case, "sees" a solid reference ground.
Have you looked inside your generator? They are easy and cheap to rebuild. Usually the brushes and bushings are all you need to replace but check for broken brush holders and shorts on the armature
You may not want to do this for a variety of reasons: but, I changed to an alternator (pretty simple) on my 1957 Chevy truck. No problems since; reliable, easier to troubleshoot (built-in regulator), and has all the advantages of an alternator when it comes to charging. One of the best and easiest swaps I made. If you are somewhat concerned with originality, they do make alternators disguised as generators. don
There are two ways the generator "idiot" light works. First, when the key is on, one side of the bulb is powered by the ignition switch run side. The other side is from the generator armature. The generator acts as a ground when engine is not running, thereby lighting the idiot light. Second is when it is running. What happens with the idiot light is almost the reverse of the first way of lighting. The armature will be the + side of the light, the ignition switch now becomes the - side of the light. Now if there were resistance either between generator and regulator, or between regulator and battery, or between battery and ignition switch, the light may light up very dimly. When you load down the battery more so, the regulator will now tell the generator to charger harder and at a little higher voltage. If any of the above 3 scenarios is present, the light will light even brighter. A good way to find out if the generator does charge the battery is to install an ammeter between battery and regulator/ignition switch, etc. Do not run the starter on the ammeter side away from battery. This will show if there is a problem or not. BTW: My old Chevy did the same thing, and so does my 54 Chrysler. In the case of the Chevy, I did replace the regulator and polarized it too. Light still did the same thing.
Ignition power is still positive, not negative. Idiot light is off because two positives will not make a lamp work. Therefore it's still a ground signal that is being fed back (weak or strong) from the charging system. Also, if it worked as you describe, the ignition switch would short or burn out.
How long do brushes last anyway mileage wise? Put a lot of miles on a gen and when I opened it up they had lots of meat left on them.
FIRST step is getting a decent multimeter and test light - if you don't have them. A few years back, I bought an INNOVA digital meter for my travel tool bag - only $25 at Walmart, OReily's also sells them. LOVE the thing, BIG numbers on the screen, and the audio continunity tester (aka 'buzz-box) has a good, loud beep for testing connections. Get a test light with a BIG ground clip, makes it easier to connect to unpainted steel, like bolt threads or a bracket. Your issue might be nothing more than than a broken wire or a loose connection. Hard to tell without a meter to check charging voltage (around 13.5 volts) at the battery and voltage regulator, look for difference in readings. I'd open up the generator for a look-see at the brushes, clean and test per the manual. You'll need to call around your area to find an electrical shop with a GROWER to check the armature. Cheap, easy to do. Also, maybe look at the points in the regulator for oxidation, clean with a point file and brake cleaner. Don't forget to disconnet the battery GROUND before ANY electrical servicing, AND follow the manual to POLARIZE the generator and regulator, then check for charging voltage. Take your '55 manual to a copy center, get the wiring diagram blown up to POSTER size. IF you only use it ONCE, it will be worth every nickle - mucho easier to study circuits and indentify wire color and gauge. Good Luck, Tim
The ignition switch terminal is more negative (in electrical potential) than the generator armature, therefore the light will light dimly. The ignition switch terminal is not shorted to ground, it is just lower than the armature terminal. ie: armature 14.3 volts, ignition switch terminal 13.5. That difference of .8 volts is enough to light the idiot light ever so dimly.
^^^^^ Positive is positive, no matter it's value in voltage. Explain how a lamp receiving positive 12 volt's from an ignition switch can ever be .8 volts and the vehicle still run ? The signal is coming from the regulator via ground that can produce a .8 reading at the idiot lamp. You'll clearly find the ground source in the diagram, not the ignition switch.
OK, an update. I took the belt off and ran the jumper cable and it would motor, fairly strong and fast, at least compared to an A model which is the only other thing I have tested this way. I took it off and pulled the back cover off and inspected the brushes and commutator. The book said to replace the brushes if they were worn down more than 1/2 way, which is great advice I guess, If I had known how long they were when they were new. I cleaned the commutator with an old commutator stone that Pop used to use to clean the one on his welder. Blew it out good and put it back on. Same as before, no real change in the performance. I took the cover off the voltage regulator and it is not solid state after all, it still has the 3 coils with the points, so I was wrong about that. Something was not exactly correct about the way the bottom of the generator was mounted to the block. They were using a castellated nut as a spacer between the housing and the bracket on the block. I managed to drop that nut, without realizing it, and when I tightened the bolt down I cracked the housing, and broke off the mounting ear. So in the end, it beat me. I'm not spending any more money on a generator. I have a self-excited alternator with an internal voltage regulator, aka "one-wire alternator" that I will put on it, just like all the other people do who cant fix shit. Its a more-or-less stock car, but by no means a restoration, so the alternator is not going to bother me a whole lot. Johnny Gee, I was reading in a book i have, "Wired for Success", by Randy Rundle, about the temperature compensation for the voltage regulator... A cold battery is more difficult to charge, because of the increased resistance, and needs a higher voltage. This temperature compensation is accomplished with a bi-metallic strip that will change according to temperature... Maybe not quite the detail you wanted , but that's all there was. Funny thing was, I had to replace the generator on my A model yesterday too, because of noise. Its just been a generator week. Thanks for everyone's help.
I'm going through engine compartment, cleaning pieces and parts from a box, looking at generator, not only is it ugly, but can see wires hanging out of armature and there appears to be a wobble on shaft. I really want to keep in original form, just starting my hunt. It looks like a new regulator has been placed on fire wall. reading posts, will make sure I buy one without an internal regulator.
If any of you guys would like a copy of a Genuine GM Service Training Manual info for refurbing a generator let me know and I will send you over a copy.
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