Put a voltage meter on the battery, Note the reading, and start the engine, the reading now with it running should be higher. I would be happy seeing 13 to 14.5 volts on the meter with it running.
Have you checked for a voltage draw on the battery when the key is in the off position. Also make sure the Alternator is charging.
What kind alternator is? Is Bosh or different kind?
Your 12 volt battery should be about 12.5 volts without the engine running. Test and verify it is. Now with the engine running test again, Voltage should now be around 13 to 14 volts. If not, then your battery or alternator are bad. To check a battery try charging it with a battery charger.
Check to see if the engine charging system is producing at least 12dc volts
A loose connection in the wiring
Check with your John Deere dealer. No, not Home Depot or Lowe's but an actual business that works on and sells John Deere mowers.
John Deere lived in Rutland, Vermont close to Middleberry. For the rest of the story check out the related link...
Check your stator or your charging system.
Yes, you can find out how much a new John Deere 320 would cost you at www.deere.com. Also, you can check out the price of a used John Deere 320 at www.tractorhouse.com.
Yes. I had to do the same thing with our john deere. We went to the john deere store, and they were very friendly and printed out a diagram for us to take home and use for free. Look in your phone book and find a john deere store near you, or check www.deere.com.
Check out this link.
Actually, the best way in order to purchase John Deere branded apparel would be to check the related John Deere gift shop. This gift shop can be found at "JohnDeereGifts".