[AT] Electrical/Generator Issues

Ben Wagner supera1948 at gmail.com
Thu Apr 26 17:54:29 PDT 2012


Hi Dudley,

Thanks so much for posting these instructions, I was able to test the 
generator according to your plan.  I don't have much good news; I guess 
the faulty wiring has done something to it.  I do have an extra 
generator (missing the pulley and all brushes) that might give me some 
parts if I need them, but I am anticipating a generator purchase, as 
well as a relay.  I think it will be cheaper to replace it then fix it, 
but I am planning to get a quote from the local repairman.

To make a long story short, I need to replace most of the wiring, 
because it is wired like a Super A (regulator) to the regular A (relay) 
light switch.  I also need to buy a new battery, since the current 
battery is history.  To further complicate things, while the tractor sat 
for two months while my life came back to order the starter has 
something messed up.  It is sluggish, even on an emergency 12 volt jump 
box.  I am concerned that the starter may have issues, too.  For a 
positive, at least I have the probability of more fun tearing apart my 
tractor again!

In the end, until I solve all these problems, I am planning to purchase 
a hand crank for my A.  Electrical is obviously not working well with 
me!  Do any of you gentlemen happen to have an A hand crank hidden 
someplace that you would be willing to sell?

I apologize for my slow report, Dudley.  I really appreciate your time 
putting together the generator instructions; they were great!

Ben Wagner


On 3/28/2012 10:18 PM, drupert at seanet.com wrote:
> Ben,
>
> When you have an old tractor with a 6V/12V Bendix electrical charging
> system that isn't working (and you have no idea why) I would start with
> the assumption that everything is bad; that is, the generator, the
> regulator and all the connecting wiring.
>
> The generator is the place to start -
>
> First, disconnect the two wires (from the regulator) to the generator.
>
> Second (after making sure the battery is good) connect one end of a
> jumper cable to the battery ground post (i.e., if the tractor is positive
> ground then connect the jumper cable to the battery positive post) and the
> other end to the frame/mount/etc of the generator.
>
> Third, connect one end of a short jumper wire to the generator "F"
> terminal and the other end to the frame/mount/etc of the generator.
>
> Fourth connect a DC volt meter (for 6 volt systems the meter needs at
> least a 20 volt scale) across the generator terminals (i.e., across the
> generator "F" and "A" terminals).  Note:  A good 6 volt generator, without
> a voltage regulator connected up to it to control/limit its' output
> voltage, will output in excess of 20 volts.
>
> Fifth (after making sure the generator belt is on and reasonably tight)
> start the engine, rev it up to "a fast RPM" and note the voltage on the
> meter.  Twenty plus (20+) volts should be observed.  If reasonably less
> than that is observed then proceed as follows:
>
> A.  Remove the generator Back Band (i.e., the cover over the commutator
> and brushes).
>
> B.  Using a Commutator Seating Stone (or sand paper/emery cloth will work
> - never mind those who say not to do this as I am sure you will use your'
> air hose to blow all the grit out anyway) and with the engine running
> sand/remove any glaze from the commutator.
>
> C.  Check the spring action in each of the three brush holders by raising
> the brush off the commutator and letting it "snap back down" on the
> commutator.  If the brush does not snap back down squart something like
> WD40 on the brush holder hinge and work it up and down until it does snap.
>   Make sure there is enough brush left for the brush (and not the holder)
> to make good contact with the commutator.  Check the short wire from the
> brush to the generator terminal (e.g., make sure the wire is connected at
> both ends).
>
> Now repeat the applicable test steps listed at the top above.  If the
> generator still does not pass then I think you will have to see a "good
> old time" auto electric man and be ready with $$$ (or try ebay/salvage
> yard and try again).
>
> I will add that I tested three generators this Spring and they all failed
> the test above but after performing the brush holder/commutator
> checking/cleaning they all passed the second time around.
>
> After you get a "known good generator" we can talk about how to check the
> regulator.
>
> Good luck - let us know how this all turns out.
>
> Dudley
>




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