polarizing a generator

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franksford

Senior Member
Interesting stuff: reading the instructions that came with a NOS voltage regulator for a 39 - 41 ford. it said to flash the battery to armature. I always thought it was flash the battery to field. My instructions for my old Sears analyzer shows two types of generator winding requiring the two different ways of flashing a generator. Not much about flashing in Ford manuals. Can anyone share there thoughts on the correct way.

Thank you

Frank
 
Ford is B circuit, unhook field & flash to battery, b circuit has field wire in middle on regulator. A circuit has field wire on end, you can use a jumper from armature to battery, quick jump

B circuit reg. BFA. Ford
A circuit. Reg. BAF. Delco

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Ford is B circuit, flash field to battery, Delco is A circuit, you can use a jumper from armature to battery
B circuit reg. BFA
A circuit reg. BAF
 
Are you sure you have the correct voltage regulator? Are you sure it is a NOS regulator for a Ford? Just because it is in the box doesn't mean it is correct, you might post a photo of it.
 
The field coils have some pretty good turns in them. When you momentarily apply a DC voltage to those coils, it magnetizes the field pole shoes. The polarity of that magnetization is important in order for the generator to start building a current flow as soon as the engine starts turning it. That current flow is what closes the cut out pole in the voltage controller and brings the generator on line.

Positive ground requires a negative power contact for polarization. Negative ground is just the opposite. When changing out a generator, a person needs to make sure that those pole shoes have a good magnetic force of the proper polarity for good function. They say you should flash the field after any change of a component of the car's charging or battery storage system but it is more important with the generator than any other component.

General Motors and others sometimes used some different theory for their charging system components but they all have a similar function in the end. "A" circuits varied the ground to the field to control voltage and "B" circuits, like Ford used, vary the current to the field coils which were grounded on the other end. Polarize an "A" circuit batt to armature. Polarize a "B" circuit batt to field. Some Ford tractors from 48 thru 52 used A type circuits for a while but a lot of them ended up being switched out to B circuits.
 
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"unhook field & flash to battery"


Does it have to be unhooked or can it be jumpered?? Engine running or not??
Paul in CT
 
Not sure I follow the procedure for polarizing the generator.

I’ve just had the generator completely disassembled so I could re-wrap the field coils with Scotch glass electrical tape. I cleaned and reassembled the unit. Can I polarize it with a 6 volt battery charger ? If so, how do I connect the charger ? No cutout presently on the generator.

Thanks - Jim
 
Conway>>>Not sure I follow the procedure for polarizing the generator.>>>


Me neither. A picture might be worth a few thousand words. If I had to guess from the picture, I'd probably momentarily touch the field wire to bat terminal on the regulator for type B. Jack E/NJ


450270
 

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The FORD SYSTEM IS THE TYPE B CIRCUIT as in Jacks drawing above. Remove the field wire from the regulator and touch it over onto the B battery terminal for a second. Thats all you have to do. This question has come up a thousand times in the past and a lot of incorrect information has been given, with much of it overcomplicated. Regards, Kevin.
 
Conway. A battery charger should not be used for testing or polarizing a generator. Its for charging batteries only. Fit your generator on to your car and polarize it on the car as per the posted instructions. I see you may be working on a model A Ford which has no regulator, so in that case just touch your cut out battery wire on to the generator terminal for a second. This will give a spark. Better to remove the cut out off the gen first. Your battery should be positive terminal connected to ground as original Ford system.. Regards, Kevin.
 
koates said:
The FORD SYSTEM IS THE TYPE B CIRCUIT as in Jacks drawing above. Remove the field wire from the regulator and touch it over onto the B battery terminal for a second. Thats all you have to do. This question has come up a thousand times in the past and a lot of incorrect information has been given, with much of it overcomplicated. Regards, Kevin.
Click to expand...

Yes Kevin, a thousand times at least! And yes, a ton of incorrect responses.
Guys should print off your (100% correct) instructions and place them in a handy reference file.
 
I can't pass it up, although I just fussed at another guy for hijacking someone else's post At least it does relate to the same general subject of "Flashing".

Did you hear about the Flasher that was going to retire but upon further consideration, he decided what the heck, he'd stick it out for another year. Merry Christmas everybody.
 
Good one Lawson. Of course you have to find it before you can stick it out. I appreciate your comments Kube. Best regards to you guys for the festive season, Kevin.
 
You do NOT have to unhook the wires to polarize the generator.
When the generator is stopped it is unhooked anyway.
I have also done it with the engine running.
On a Ford you flash the terminal right next to the BAT. Terminal.
On a GM you flash the terminal right next to the BAT. Terminal.
They are arranged differently on Ford. And Delco. Opposite of each other.

I haven’t had to polarize a generator since last Friday.
 
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