A 12 volt conversion looked like the 4th of July

tackhammertime · Oct 20, 2009

I have been getting the alternator on the A to complete the 12 volt conversion. Here is what I did. The wiring harness is good on the tractor so I used the Bat. wire in the harness from bat on the alt. to amp gage were it was already hooked. then wire from the other side of the amp gauge to the starter term. at bat cable. When I connected the bat. cable to the bat. wire from starter got hot sparks flew and amp gauge busted. Whay did I do wrong. The only thing I did different on the H was new wire from alt bat term to amp guage.

Anonymous-0 · Oct 20, 2009

The Battery is probably wired up as a positive ground. Make sure it is negative ground before you hook up the alternator or there is a good chance you will burn up all the diodes in the alternator.
Chuck

tackhammertime · Oct 20, 2009

Yep it was hooked up positve ground. Changing it to neg. ground is ok? Why were they positive ground?

Bob M · Oct 20, 2009

Connecting the battery negative post grounded is an absolute requirement when using an an alternator as you have discovered!

Connecting the battery positive grounded to an alternator - even for an instant - will generally ruin an alternator. (Internal diodes and regulator are highly intolerant of reversed polarity...)

----

Why were most OEM 6 volt generator system positive ground? Good question! I've yet to find a compelling argument supporting one polarity over the other for generator-equipped systems.

rustred · Oct 20, 2009

6 volt is pos. ground from factory due to physics that play a part in the prevention of sleeve deteriation by those little tiny air bubbles that attack them. once you go 12 v you need neg. ground.

tackhammertime · Oct 20, 2009

Thanks I love to learn something new everyday.

HENRY E NC · Oct 20, 2009

Almost all vehicles were 6 volts until sometime in the 50's I think. Current flow was thought to be different at that time. I cant remember tonite but 12 volt reqires less amperage than 6 volt and smaller wire can be used. If this is not correct I am sure someone will tell us so. Henry

tackhammertime · Oct 21, 2009

Got it done no more fire works fried the amp meter saved the alt. shows charge when running thanks.

A 12 volt conversion looked like the 4th of July

tackhammertime

Member

Anonymous-0

Well-known Member

tackhammertime

Member

Bob M

Well-known Member

rustred

Well-known Member

tackhammertime

Member

HENRY E NC

Member

tackhammertime

Member

Similar threads