Battery charging problem

[CCWKen]

When I built the "Kenbota", I replaced the tea-cup dynamo and rectifier with a 42A Mitsubishi alternator. I was running halogen lights and some heavy draw items like 12v convertible top pumps (2) and a 12v Linear Actuator. And a BIG battery. The pumps and actuator aren't used any more (grader blade) but I kept the alternator.

 

[100 td]

As far as I can see from the attached diagram, the following is correct.

There's no extra coils in your diagram.

The coils are in the dynamo, they aren't shown, possibly split 4 coils for each circuit.

It's set up to run the lights on AC and charge the battery with DC.

No. I thought that initially, but it appears that if you follow the light circuit, the lights are powered from the "T" terminal of the light switch, the "T" terminal is connected to the "B" terminal which is 12V DC direct from IGN switch/"B" terminal on regulator. Battery is charged via "B" terminal on the regulator as normal when engine running

If the lights aren't on, there's no flow of AC.

No. The AC circuit is brown wire to the "AC" terminal, and yellow wire to "AC" terminal via "S" terminal. Completed AC charging circuit whenever dynamo is spinning.
Additionally, when the light switch is activated, white wire from dynamo to "G2" terminal is connected to "S" terminal to "AC" terminal, adding some output from the dynamo to the circuit.

The OP stated there were separate modules for the rectifier and regulator. Perhaps the regulator is used strictly for gauges or something. That's why I'd like to "see" what he has.

Yes, I said this circuit may be similar to his as it has a 3 wire dynamo and additional switching with the light switch. What he actually has, we will have to wait for the pics and info and see.

 

[100 td]

When I built the "Kenbota", I replaced the tea-cup dynamo and rectifier with a 42A Mitsubishi alternator.
View attachment 445210

This is the ideal way to flick the little low output dynamos and get some decent output. (For me, ideally an internally regulated unit with only one wire to a charge lamp, and main output to battery, this may be one, not sure)

 

[malced]

Hopefully you will find pictures of the alternator etc attached to this.
The alternator has 6 coils in the stator with differing windings on some of them.
I have not shown the internal links inside the light switch on the schematic, but to clarify this. The light connections are totally isolated from the alternator feeds, there is no cross connection of any kind with the ac supply. When the engine is running the alternator supply to the regulater is via the brown and the yellow wires(yellow to red on schematic) so one phase (white wire) is not in use. When the lights are switched on the brown and white wires supply the regulator and the yellow wire is isolated. In effect, only one phase is in use at any time. This makes it, to all intents and purposes a two phase system.
Given that this is just a compact tractor it seems an unneccessarily complicated set up.

 

[100 td]

I won't get a chance to go over this now for possibly a couple of days, but at a quick glance it appears that your drawing is very similar to the one I found in regards the dynamo, light switch etc. (You need to change it to English!)
Have you noticed the arcing/burning in your photo under the main switch?

 

[100 td]

Check your switch circuit diagram, the white and yellow join when the lights are switched on in the schematic, I doubt the switch is different?

 

[malced]

Glossary of terms, french - english: Comutateur principal = Ignition switch
Voyant de charge = Charging light
Voyant d'huile = Oil pressure light
Redresseur = rectifier
Interrupteur de lumiere = lights switch
Compteur heures = hour counter
Fusible = fuse
Relais = relay
Prechauffage = preheater

As regards the 'burn marks', they are where a piece of metel has been welded into the casing to accomodate an aftermarket ignition switch.

 

[malced]

Check your switch circuit diagram, the white and yellow join when the lights are switched on in the schematic, I doubt the switch is different?

No, they do not join. When the light switch is off the yellow and red wires make a circuit to the regulator and the white wire is isolated. When the lights are switched on the circuit is made by the white and red wires with the yellow wire now being isolated.

 

[100 td]

Looking at the diagram it appears that there is no separate regulator. It may be contained in the inbuilt rectifier. From the other switch diagram, it shows the connection of the white and yellow together when the light switch is on. This would boost the dynamo output when the lamps are on. Not certain, but this may be a fault in your switch. Do you have any pictures and circuit of the coils in the dynamo?
Can you test the "no load" output of dynamo at 4000 rpm?

 

[Xfaxman]

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As regards the 'burn marks', they are where a piece of metel has been welded into the casing to accomodate an aftermarket ignition switch.

When was the welding done in relation to the current problem?