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Subject: 6V Polarization

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Mike    Posted 01-28-2019 at 14:44:38 [URL] [DELETE]        [Reply] [Email]  
  • 6V Polarization
  • I have the following note in manual for polarization and was wondering why the procedure is different between the earlier 6 Volt A systems versus the later 6 V B systems/regulator models. Just curious.

    "On the 8N tractors, use a jumper wire or a flat blade screwdriver to momentarily short between the "BAT" and "GEN" terminals on the regulator. Sometimes they will be marked "BAT" and "ARM". Make a spark and it's done. Make sure to short BAT to ARM and not to FLD. If the three terminals are all in a row, they should be marked B-A-F. BAT and ARM are right next to each other.

    The polarization mentioned here should be done any time you notice the generator is not charging, and you just did some sort of repair or maintenance where the battery or generator was disconnected. Often the generator will maintain correct polarity without doing this step, but occasionally it will need to be polarized to re-establish correct polarity with the tractor wiring.

    If you have one of the later 6-volt Ford or other tractors, it may have the type "B" system. Look for the regulator terminals to be marked A-F-B. If the BAT terminal is not right next to the ARM terminal at the regulator, this is a type "B" system. The "B" systems take a little more work to polarize. Disconnect the FLD terminal, touch the FLD terminal to BAT, then reconnect the FLD terminal."

    Mike    Posted 01-29-2019 at 08:23:16 [URL] [DELETE]        [Reply] [Email]  
  • Re: 6V Polarization
  • Thanks gents. I've updated my notes in my 8N and 861 manuals.

    Tim Daley(MI)    Posted 01-29-2019 at 04:20:31 [URL] [DELETE]        [Reply] [No Email]  
  • Re: 6V Polarization
  • Mike-
    The polarization method is different on them because it matters how the A and B circuits are grounded. The fields are grounded are different. Only the very first 9N-10000-A unit, a 2-wire/2-Brush, 'B' Circuit Design unit, 7 AMP output, and which used the 9N-10505-A special Voltage Regulator, and the FAC-10002 NAA unit, a 3-Wire/2-Brush 'B' circuit Design, 20 amp output, used Ford Tractor generators that had the 'B' Circuit Design. All others were 'A' circuit designs. With the 9N-10505-B cutout you polarize by arc-sparking the two terminals on it with a jumper wire. BTW, if you have an early 9N-A generator and do not have the voltage regulator for it, you can use the FAG-10505-A VR, but will need to modify how its mounted. Some later generators did have the barrel terminals marked -see picture. I'd say if you can't determine from the outside if a stud has or is missing the insulated rubber or phenolic washer or not, you will have problems. An internal inspection is need like JMOR says, but if you don't know what to look for, take it to a starter repair shop, they'll tell ya.

    Tim Daley(MI)

    Mike    Posted 01-28-2019 at 15:15:40 [URL] [DELETE]        [Reply] [Email]  
  • Re: 6V Polarization
  • I found an exhaustive dialog between JMOR and Keith on the subject in the archives. Thanks JMOR. Last question. Is there a way to distinguish between the ground and field terminals on the casing if the insulator is missing?

    JMOR    Posted 01-28-2019 at 15:33:06 [URL] [DELETE]        [Reply] [No Email]  
  • Re: 6V Polarization
  • No wire connected to generator ground terminal inside the barrel, but field coil is connected to terminal inside the barrel.

    Mike    Posted 01-28-2019 at 16:59:52 [URL] [DELETE]        [Reply] [Email]  
  • Re: 6V Polarization
  • Thanks.

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