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Does a 1946 John Deere A have a negitive or positive ground off the battery??
Looking at the web page TractorGata for that year under electrical it states
ground: positive
So does that mean the pos. cable off the battery go to ground and the neg. go to the starter ?
I have'nt had this tractor but a couple of months and was changing out the battery that would'nt hold a charge and I hooked it up neg. to ground and pos. to the starter. and it starts up fine as it did before. and if I did have it hooked up wrong would it even start?
 

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it will start but now it will not charge, you will have to polarize the generator. When ever I need to do it I have to look up the right way, its not hard to do but off hand I don't want to steer you wrong so soundguy or another member will get you on the right track.......................................mike1111
 

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A couple of variables whether it's positive or negative ground.
If it has the original generator on it then it should be positive ground.
If it has been converted to an alternator then it will most likely be negative ground.
The starter doesn't care which way it's hooked.
 

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Does a 1946 John Deere A have a negative or positive ground off the battery??

Yes, your 1946 John Deere A has a positive ground.

Take a look at the diagram below.
Starting and Lighting.jpg

So does that mean the pos. cable off the battery go to ground and the neg. go to the starter?

Yes, note the ground cable (Key 12) is connected to the positive (+) terminal on the battery and the negative cable (Key 1) goes to the starting motor.

if I did have it hooked up wrong would it even start?

Yes, but as mike1111 mentioned, the generator will need to be polarized.

One method of polarizing the generator is to attach a jumper wire with an alligator clip to the BAT terminal on the voltage regulator.

Briefly touch the other end of the wire to the GEN terminal a couple of times.

Be absolutely sure that you do not touch the FLD terminal while polarizing the generator to battery connections.

Generators normally have two terminals. F or field is the ground or "regulated ground" terminal, and A or armature is the Hot or "regulated charging" terminal.

Take a look at the diagram below.
Voltage Regulator 1.jpg

Hope this helps.
 

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Normally all generators are positive ground. Some delco generators for cars were negative ground and they usually had a green lable where it has the Delco Remy tag. But 95% of generators are positive ground with the red tag. ALL alternators are negative ground and you will destroy the alternator in less than a half second if you hook it up backwards.

Polarizing is not necessary for most generators. Most of them rember their magnatizm. The easiest way to find out if the generator needs to be polarized is after starting the tractor check to see if there is power at the "gen" post of the generator. There wont be alot of power until the fields are excited with the regulator. Generally if you put a voltage tester on the fields (by accident) you may see the needle twitch yet not come on solid. Something in the design according to my buddy charlie.

If you are missing the tag on your generator and you cant tell the color, use a digital voltage tester. Placing the positive lead on the frame and the black on the gen of the generator you should just see the voltage of the generator (idle about 3-4 volts, no regulator). If it is positive ground the generator willput out voltage and the meter will have the minus ( - ) before the voltage value. This test is done with out any wire connected to the generator.

Also be aware there are Delco Remy Starter Generators out there that were used on the older lawn mowers. They look just like the regular generators, yet they have a extra set of windings in there that allow the generator to work as a starter.

Isnt it fun the headaches of using a generator? Hence the reason alot of users went to a alternator. Alot less headaches.
 

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The rule of thumb i was given is "anything built before 1961 will be a positive ground"
I dont know about the date or know the reason, but just what i was told
 
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