Ferguson -still- not charging

So I'd suggest you get an s10 alternator and switch to that. There is also a diagram and write up on generators in the Archive also that may help you.

The contacts of the regulator are supposed to open when the output of the generator falls below about 13 volts, so the battery doesn't drain through the generator, and When this happens the light goes on.
Did you try opening and closing the contacts as you describe at different engine speeds? If so, did they close more easily at higher speeds?

Maybe the field winding has gone open. It's supposed to be 6.2 ohms (assuming you have the Lucas C39/2 generator). That 4 volts seems high to me, but only by intuition.

When you say the other terminals show no power - one (D for dynamo) is supposed to be connected to the output terminal on the generator, and the other (F for field) connects to the smaller field terminal on the generator. Something is definitely wrong with that picture, since you say you see 4 volts at the field terminal.

Here is a bit of text from the service manual:

"The function of the regulator is as follows:

1. Breaks the circuit between the battery and the dynamo if the dynamo voltage falls below the battery voltage. This prevents discharge of the battery through the dynamo when the tractor is stopped or idling.
2. Controls the maximum voltage reached by the dynamo.
3. Controls the maximum current output of the dynamo.

".....if the voltage or amperage reaches a predetermined limit, the regulator breaks the circuit to the field and cuts in a resistance. This immediately cuts down the voltage and amperage until the contact points close when the output rises until the circuit is again broken by opening contact points. These cycles occur so rapidly that the points vibrate at a high frequency and thus hold the output at a constant predetermined maximum.

"The voltage regulator is thus permitted automatically to to cope with electrical loads as applied, and maintains the battery at full charge without overcharging."

There is also a bunch of stuff about temperature compensation - to summarize: when it's cold the voltage to charge the battery is higher.

So I think the generator is faulty. If you have an auto electrical shop somewhere around, or even an older regular repair shop, they may have a rig to test it. If it were me at this point I would take the generator in and get it checked out.

Regards,
Jim W in coooold Ontario Canada.

After having read your answer I am not sure either. I measured the 13.2 on the battery.

>The contacts of the regulator are supposed to >open when the output of the generator falls >below about 13 volts

This COULD explain the whole situation. If the generator is producing just slightly more than 13 Volts this won't be enough to close the regulator contacts. When I force them to close they sometimes stay closed but most of the times open up again after a few seconds. Perhaps the generator is not "dead" but producing electricity just below the limit that the regulator requires.

>Did you try opening and closing the contacts as >you describe at different engine speeds? If so, >did they close more easily at higher speeds?

I closed them at the same engine speed each time.

>Maybe the field winding has gone open. It's >supposed to be 6.2 ohms (assuming you have the >Lucas C39/2 generator).

Can I measure this without opening the generator?

>That 4 volts seems high to me, but only by >intuition.

Perhaps I wasn't carful when measuring. I'll do an other test and read the instrument more carefully.

>When you say the other terminals show no power -
Hmmm, I wonder if I have mixed up the contacts on the generator. I might have measured on the small contact. There are no letters on the generator. The smaller one is located half an inch ór so higher than the bigger one. The higher should then be "F", right? >Here is a bit of text from the service manual:

Interesting, thanks!

>These cycles occur so rapidly that the points >vibrate at a high frequency and thus hold the >output at a constant predetermined maximum.

The text above was what made me think the generator might be "almost okay". When I force it to start charging it does so. Sometimes it continous for a while and sometimes it stops charging almost instantly. When I force the contacts together the generator might be producing 13.19 volts or so... I see no vibrating of the contacts. They are either on or off.

I wonder: If the generator is good enough to charge 13 volts but no more it can't be that bad can it? Would an inside cleaning help? Could this be caused by worn carbon brushes?

If you have an auto electrical shop somewhere around, or even an older regular repair shop, they may have a rig to test it. If it were me at this point I would take the generator in and get it checked out.

I suppose that is a good idea, but still I would like to see if there is a way to check the generator properly. Could I perhaps connect a flashlight battery to one termainal on the generator to get it started and then use a voltage meter on the other one to see what comes out.

One thing more: Polarising: When I mounted the new regulator it said in the instruction that I sould connect D and F until >I saw a spark. I did this on the regulator. Should I have done it on the Generator instead or doesn't it matter?

Kevin: A Chevy generator would probably be a good solution. There are two reasons why I won't do it that way. 1. In Sweden Chevys are quite rare and that goes for Chevy generators too, so if I'd replace the whole system I would probably use an alternator. (I have one from an old Plymouth Valiant). 2 Even if my Ferguson looks really sad at the moment I still want to keep it as close to what it looked like 50 years ago as possible. One day it Will get new paint and better tyres!

Tomorrow I will quit work rather early. Hopefully I will be spending the evening with the tractor.
Cheers
Anders

>>If there is more than one coil making up the field, it is possible that one has gone open and the generator is not operating at full capacity, but this is pure speculation on my part.

>Maybe the field winding has gone open. It's >supposed to be 6.2 ohms (assuming you have the >Lucas C39/2 generator).

Can I measure this without opening the generator?

>>Maybe...I think so...try measuring from the field terminal to ground. >When you say the other terminals show no power -
Hmmm, I wonder if I have mixed up the contacts on the generator. I might have measured on the small contact. There are no letters on the generator. The smaller one is located half an inch ór so higher than the bigger one. The higher should then be "F", right?

>>Yes. It just takes a bit to energize the field, so it doesn't need such a heavy wire. When the battery has been quite discharged such as when you've run the starter for a while, the generator needs to source quite a bit of current to recharge, hence the heavier wire from its output terminal. >These cycles occur so rapidly that the points >vibrate at a high frequency and thus hold the >output at a constant predetermined maximum.

I wonder: If the generator is good enough to charge 13 volts but no more it can't be that bad can it? Would an inside cleaning help? Could this be caused by worn carbon brushes?

>>I doubt it really, but it certainly won't hurt to clean it up, and if you're going so far as to disassemble, new brushes now will save you doing this again in a decade or two. Don't sand the copper on the armature where it makes contact with the brushes; that is too aggressive; it is better to use an eraser.
A common problem is worn bearings, so it would be worth checking those too while you're in there.

I suppose that is a good idea, but still I would like to see if there is a way to check the generator properly. Could I perhaps connect a flashlight battery to one termainal on the generator to get it started and then use a voltage meter on the other one to see what comes out.

>>I am not sure what you mean here but I think you can do most testing by measuring the various things we've discussed so far with the generator in situ.

One thing more: Polarising: When I mounted the new regulator it said in the instruction that I sould connect D and F until >I saw a spark. I did this on the regulator. Should I have done it on the Generator instead or doesn't it matter?

>>It should have been on the generator. The idea is that the field coil(s) are an electro-magnet, which is why they need to be energized. They retain some residual magnetism after the tractor stops running though, and this residual magnetism is of some polarity depnding on whether your system is positive or negative ground. Once the generator starts turning the magnetic field of the field coil(s) builds up in the direction of the residual magnetism. "Polarizing the field" is done especially when changing from positive to negative ground. A wire from the the battery (non-ground) terminal is touched briefly (a few seconds only) to the field terminal in order to ensure that the field's residual magnetism is of the correct polarity. From then on it will charge properly. Sometimes if a generator has been sitting around non-operational for 20 or 30 years the residual magnetism in the field is so low that it also needs to be "polarized".

JIm