BatteryDear Ole Mechanic;

I have a battery problem in my restored 1953 Golden Jubilee Ford tractor.  The restoration was done about a year ago by a person who has the reputation of being a top notch restorer.  Ever since the restoration, the battery keeps running down.  Because the tractor is a show and parade tractor, it can sit for two or three months without being started.  After sitting for two months, I went to start it and the new 12 Volt battery was dead--flat--without even enough charge to light up a test light.  I took the battery back to the store it came from.  They charged and tested it and said it was OK.  Three months later, it was the same thing--a dead battery.  This time I charged it and left it on the bench--not in the tractor.  Two months later, I put it in the tractor and it was fine.  The tractor started right up with no problem.  After two months in the tractor, it was dead again. I charged it up again and a week later the tractor started right up.  Another week after that, it still started fine.

What gives?

During the restoration the tractor was converted from 6 Volt to 12 Volt by using a one-wire alternator, all new wiring, all new 12 Volt lights and bulbs and a 12 Volt coil.  Using a test light, I can not find a battery drain when the key is off.   Help!

Run Down Battery

 

Dear Run Down;

The restorer did not make any mistakes when he restored and rewired your tractor.  His only error was not telling you about the unusual characteristic of  one-wire alternators or perhaps he is not aware of that characteristic.  That fact is that one-wire alternators have a microchip in them that allows their one-wire operation.  That microchip draws from 300 to 500 milliamps even when the switch is off and the tractor is not running.  That small draw on the battery will run the battery down very slowly over a period of about one to two months.  That 300 to 500 milliamp drain is not enough to light up most test lights.  If you start and run the tractor daily or at least once a week, that small draw is not enough to drain the battery in that short amount of time and the battery will charge back up while the tractor is running.  Keeping the battery from running down during longer periods of storage is simply a matter of disconnecting the battery.  I prefer to use one of the battery-disconnect switches that are available at auto parts stores.  They can also be ordered by mail from J.C.Whitney®.  There are several different designs of switches and they cost anywhere from under $10 to over $30.  One advantage that a battery disconnect offers is a greatly reduced risk of fire while the tractor is stored.  I prefer a disconnect  that mounts directly to the battery.

The one-wire alternator does make a clean installation and it is easy to hook up.  The only drawbackis that small drain on the battery.  Have fun with your Jubilee.

Herr Professor Nuzanbolts