Tractor Repair: converting a Ferguson to30 6 volt to 12 volt, ferguson to30, field terminal

Question
Thank you for your reply on 032108 on how to do this "job".  I have done this but it runs the battery down overnight with the switch off.  What have I done wrong possible or what needs to be done to fix it.  Thanks again for you advise.   Carl

Answer
Hello,

  Either the alternator is not wired correctly, or the alternator is no good.  The keyed power should go to the field terminal.  It should not be live power all the time.  The output terminal has an isolation diode inside to let current out of the alternator, but not let current go back in after it is shut off.  If the diode is bad, it could have a constant draw.

                             Arnie