Vic 6 charging system.

[Guest BretK]

Ok, so now that I am driving around the block in my Vic six, I am not entirely sure the charging system is working. The ammeter on the dash seems to be reading opposite as it he n needle is always near or below midline, although the fine print on the gauge shows that is charging, if I turn on the headlights it drops lower. How do I diagnose the generators issues?

thanks!

[TexasJohn55]

An ammeter only shows charge rate in amps relative to the load. If the battery is "hot" and no load, it will show a low charge rate. It simply shows whether current is flowing into or out of the battery. A dead battery will cause a high charge rate but if additional loads such as headlights and heater blower are added, the charge rate remains high but the ammeter will show lower charge rate because less current is flowing into the battery. When the load exceeds the capacity of the generator (ie: 35 amps) the meter will show a discharge even though the generator is at maximum capacity. Keep in mind that the meter displays amps. To effectively diagnose charging system you also need a volt meter to see if regulator is functioning properly. A good hot battery with no accessories on should require a low charging rate but voltage should be around 13.2v or higher. A hot battery with engine off should show appx 12.4-12.7 volts. I don't know the amp rating of your generator, but you can also check the output of the generator with an inline amp meter to see if it meets design rating. READ POST SLOWLY as it may be confusing at first. ...TexasJohn

[Guest DodgeKCL]

I don't think his car has a regulator and it's 6 volts? If I'm right this is a 'Chrylser' car and it's not a 12 volt Dodge. (Not until much later) However everything TexasJohn says fits otherwise. Most of our old cars used the battery as the 'regulator' and as the generator 'load'. I find most of the problems like you have just mean the car needs a new battery. Unfortuntely even a bad battery will allow the buss to get up to 7-8 volts (or 14-15volts),it's just that the battery ain't taking on a charge. You need to go back to basics. Get a hydrometer and see if the battery electrolyte is getting up to 1.25 or so. If it's down near 1.1 then you're chasing an end of life battery. They're hard to pin down unless you check the specific gravity. The old guys used to check this 1st thing before doing anything. But then batteries were replaced every year then. NAPA and Carquest sell hydrometers. You could charge the battery up,in car, on a charger and see if it gets to 1.25 or higher. If it does then the problem is either sticking points on the reverse current cutout(the box on the top of the generator)a slipping fan belt but most likely not the generator per se. Wearing brushes are the biggest problem and they cause the ammeter to flicker as they start to lose contact with the commutator on the generator's armature.

Edited July 11, 2013 by DodgeKCL (see edit history)

[TexasJohn55]

Thank You for the "save" DodgeKCL !! I'm glad you showed up. I should have stayed on my own forum. I sometimes wander when I just read "new threads" instead of Buick Forums. Sorry bout that, I should be asking questions here instead of trying to help. The original poster is in good hands and I bid you goodbye. TexasJohn

[Guest BretK]

Guys, thanks for the input. It is a 6 volt car, new battery, no regulator, northeast generator, cutout on top, (how do i test,? it moves freely) screw in 6 amp fuse in the back (good fuse) I guess I need to figure out how to test the generators output properly. Keep the suggestions coming

[Ron Lawson]

If the needle is reading discharge Have you got the battery polarity correct? It should be positive earth

[Dwight Romberger]

If the generator is charging, you can remove the negative battery cable (assuming positive ground) and the car will keep running. If not, it will stop. Doesn't get more simple than that:cool:.

Edited July 12, 2013 by Dwight Romberger (see edit history)

[Guest DodgeKCL]

If you reverse the original battery polarity when you install a battery, the generator will melt down the moment you start the engine. Been there,done that. But I have a feeling that these old generators lose their polarity chage and need to be polarized every once in awhile. I know it doesn't make any sense but I've been known to connect a wire from the starter motor battery cable over to the generator side of the cutout just for the hell of it. Does it charge up the residual magnetism on the generator steel parts? Yes. Does it increase the residual charge on the generator? I think so. The reason I feel it is necessary is because the reverse current cutouts actually do pass about 3 amps,sometimes more,backwards into the generator degrading the magnetic charge before the cutout relay finally snaps open. And I think this is cummulative. (In fact the cutout won't snap open until at least 3 amps or so has been flowing backwards to kill the induced magnetic pull in the cutout bobbin caused by the current flow out to the car's buss.) How do you test a cutout? First of all ,don't touch the relay arm or the spring or anything else. They all are part of the calibration as to when the relay closes or opens. It has to be put on a bench with a varible power supply and a good voltmeter and set to the manufacturers specs by bending the spring mount. If you don't know how to do this,don't touch it. However they were known for having burned points after a while and these can be cleaned with a piece of fine emery cloth pulled through the points while you GENTLY hold them closed against the emery cloth. Then clean the emery cloth and point dust off with lacquer thinners. Do not use varsol as varsol leaves an oily residue. Dwight's idea of disconnecting the battery will tell you if the generator is outputting but not how much and at what level i.e. voltage. The ammeter should show a cummulative discharge as things are turned on before starting. Then as the engine starts the needle will swing very high, around 20 amps to put the starting current back into the battery. However if you slow the engine down, the needle should suddenly drop below 0. This is the cutout relay opening and taking the generator off line. If it's night time you would see the headlights go somewhat dim as they drop to the battery voltage which is a couple of volts less than the generator voltage. Then the opposite happen as you rev up the engine or drive away from a stop sign. (If you're slow in shifting, the cutout will open and close everytime you shift.) The fuse on the cutout is to protect the field windings and basically the generator. Apparently the generator could go beyond it's set output and burn up. The current output, not the voltage output, is set by adjusting a 3rd carbon brush which 'shades' some of the commutator by not allowing those segments to output current. Never understood why every manufacturer set their generator to a different maximum current. As far as I can see they should all be set to 20 amps and that's it. You can set them by leaving your headlights on for several minutes and then starting the car. The ammeter will show max charge for several minutes,you need a high idle, and tell you what the generator is set to. You have a new battery so that's out. That's about it. I'm drained of ideas. The old guys never used anything but a forked ammeter that they jammed into the tar on top of the battery to test each cell under load, a hydrometer, and the ammeter on the dash. They never tested for voltage. I've talked to them and they all say "the car was 6 volts what else was it going to do?". And I do believe that these old systems were current based. Our new cars are voltage based, that's why we have a voltmeter on the dash and no longer have an ammeter. Any clues in all this?

Edited July 12, 2013 by DodgeKCL (see edit history)

[Guest BretK]

Well the engine dies if the neg lead is disconnected when the engine running. Tried repolerizing the field, no luck. I think I need to remove the Genny and send it off to the rebuilder. Any ideas who to send it to?

[startergenrebuilder]

Before you take it off, I may be able to help you by giving you a few tests to do on the car first. It is not a good idea to remove the battery cable while running as a test, it can create a voltage spike and cause damage to some things in the system. Do you have a volt meter? First step is to see what the voltage is when running. It should read 6.2-6.5 when sitting and jump to over 7 volts when the engine runs and the generator starts charging. Give the throttle a quick boost to make sure the generator excites (if it's going to). The next step would be to polarize the generator and if still no charge then we can bypass the cutout and eliminate that from the equation. Feel free to contact me directly if needed. I'd be glad to help. If your generator and cutout end up needing service, I can help you there too.

-Jason

[Dwight Romberger]

Sorry about the possible voltage spike. I didn't know that was a possibility. Thanks Jason.

[h=3] Jason is right. Do some more testing before you send off the generator. You should know what is wrong before you consider a rebuild.

Since you tried repolarizing, try bypassing the cutout switch.

These two threads might be helpful.

Test voltage regulator [/h]

[h=3]Not charging[/h]

Edited July 13, 2013 by Dwight Romberger
tried to get rid of bold type (see edit history)

[Guest BretK]

Jason,

6.5 volts off, then 6.8 to 7.2 volts running with it bouncing all over the place between 6.3 and 7.3. The generator output when checked with across a chassis ground is around 8 at idle, and seems to drop to 5 something when the engine throttle is applied. :confused:

[startergenrebuilder]

Bret,

I just replied to your email. Give those tests a try and let me know what you find.

-Jason

[Guest BretK]

Well, I thinks with much help from jason (thanks Jason!) it appears the cutout is the problem. So off to Jason it goes for rebuilding.

[Guest 1930]

If you reverse the original battery polarity when you install a battery, the generator will melt down the moment you start the engine. Been there,done that. But I have a feeling that these old generators lose their polarity chage and need to be polarized every once in awhile. I know it doesn't make any sense but I've been known to connect a wire from the starter motor battery cable over to the generator side of the cutout just for the hell of it. Does it charge up the residual magnetism on the generator steel parts? Yes. Does it increase the residual charge on the generator? I think so. The reason I feel it is necessary is because the reverse current cutouts actually do pass about 3 amps,sometimes more,backwards into the generator degrading the magnetic charge before the cutout relay finally snaps open. And I think this is cummulative. (In fact the cutout won't snap open until at least 3 amps or so has been flowing backwards to kill the induced magnetic pull in the cutout bobbin caused by the current flow out to the car's buss.) How do you test a cutout? First of all ,don't touch the relay arm or the spring or anything else. They all are part of the calibration as to when the relay closes or opens. It has to be put on a bench with a varible power supply and a good voltmeter and set to the manufacturers specs by bending the spring mount. If you don't know how to do this,don't touch it. However they were known for having burned points after a while and these can be cleaned with a piece of fine emery cloth pulled through the points while you GENTLY hold them closed against the emery cloth. Then clean the emery cloth and point dust off with lacquer thinners. Do not use varsol as varsol leaves an oily residue. Dwight's idea of disconnecting the battery will tell you if the generator is outputting but not how much and at what level i.e. voltage. The ammeter should show a cummulative discharge as things are turned on before starting. Then as the engine starts the needle will swing very high, around 20 amps to put the starting current back into the battery. However if you slow the engine down, the needle should suddenly drop below 0. This is the cutout relay opening and taking the generator off line. If it's night time you would see the headlights go somewhat dim as they drop to the battery voltage which is a couple of volts less than the generator voltage. Then the opposite happen as you rev up the engine or drive away from a stop sign. (If you're slow in shifting, the cutout will open and close everytime you shift.) The fuse on the cutout is to protect the field windings and basically the generator. Apparently the generator could go beyond it's set output and burn up. The current output, not the voltage output, is set by adjusting a 3rd carbon brush which 'shades' some of the commutator by not allowing those segments to output current. Never understood why every manufacturer set their generator to a different maximum current. As far as I can see they should all be set to 20 amps and that's it. You can set them by leaving your headlights on for several minutes and then starting the car. The ammeter will show max charge for several minutes,you need a high idle, and tell you what the generator is set to. You have a new battery so that's out. That's about it. I'm drained of ideas. The old guys never used anything but a forked ammeter that they jammed into the tar on top of the battery to test each cell under load, a hydrometer, and the ammeter on the dash. They never tested for voltage. I've talked to them and they all say "the car was 6 volts what else was it going to do?". And I do believe that these old systems were current based. Our new cars are voltage based, that's why we have a voltmeter on the dash and no longer have an ammeter. Any clues in all this?

Knowing very little about electrics I cannot explain why the earlier D.B cars can have the battery terminal revered with no adverse affect as far as I have read except the gauge not reading correctly.

Alot of good information here regardless and appreciated by all I am sure

[1936 D2]

Bret,

I just replied to your email. Give those tests a try and let me know what you find.

-Jason

Ohhhh.... Except all us others following the info on this forum don't get the benefit of the description of the tests used. Shucks.

Sounds like it may have been some good stuff. The tests apparently isolated the problem to the cutoff.

Sigh...

[Guest BretK]

Ohhhh.... Except all us others following the info on this forum don't get the benefit of the description of the tests used. Shucks

Sounds like it may have been some good stuff. The tests apparently isolated the problem to the cutoff.

Sigh...

I ran a direct lead from the bat side of the cut out to the bat and checked voltage across. It would bounce around a lot. Took a vid of the cutout, it showed it opening and closing a lot. Held cutout closed manually while checking voltage, it stabilized somewhat at 6.8 to 7 volts showing charging. I sent my cutout to Jason for rebuilding and got a cheapie solid state cutout off flea at to use in the meantime.

bret

[Dwight Romberger]

Sounds good Bret.

Thanks for the info.